I cannot believe the Switch has been with me for almost 6 years now (got my hands on one in June 2017). It has also been my main source of gaming for the period, with PC in second and mobile in third. 

When the og Switch was announced all the way back then, many people were discussing the possibilities of an actual performance gain from the dock compared to the handhled device, as in more memory, more processing power, etc. Instead we all know what we got, which is a simple docking station used mainly to draw higher doses of electrical power.

Six years have passed and A LOT has changed in the tech department. Also, the Switch is one of the most successful consoles of all time, if not the most, so Nintendo has some room that they just did not have back then technology wise. With job postings for a next generation console already on the streets, I think this discussion could come back so we can use the knowledge of the community.

I'm no expert in hardware tech, but I would very much like if the games could actually run way better when docked compared to the mobile experience. It would be something like "performance mode/quality mode", but on the dock you would always get the possibity to have the very best scenario.

Would it now be possible to add extra juice to the dock of a potential "Switch 2"? Or is that still a bit too unpractical in the engineering department?

I know some would say that that could hinder the general experience of the users, who would not have the "same game feel in both modes" that is one of the selling points for the current Switch. But let's abstract that for a moment and only concentrate the discussion in the yay or nays of a "moar powerful dock", mainly if it would or not be possible and what could be done for it to happen.

It's likely very possible to have the dock give a bigger boost to the next system than the dock gives to the Switch. The dock of the Switch is very simple tech that is merely recognizing the Switch is hooked up to an AC adapter and HDMI, and thus unlocking its power that it can't use when running off a battery.
But we have to consider cost here and how much Nintendo wants to make. If Nintendo makes a dock for the Switch 2 that gives a higher boost in performance than the current situation, they'll almost surely pass the cost onto us. The Switch 2 is already not unlikely to cost $399.99, and this would all but guarantee it.

Not unpractical per se, but costly. We're talking two sets of hardware for a single system (if external GPU is what you have in mind). Plus, if Nintendo sticks to current form factor, the biggest bottleneck will remain a CPU, which can be installed only on a console itself and can't be downclocked too much (if at all) to maintain seamless integrity between docked and undocked gameplay. With adequate cooling (boosted by the new dock perhaps), they could push even more power through existing GPU, so as it stands right now, that's the only viable/cost effective way of adding extra "juice".

Edit: if the current form factor is here to stay, and Nintendo continues to work with nVidia, the way I see it, at best we're getting Orin equivalent SoC (based on Ampere architecture, around 4x boost in performance), better cooling solution (also from the dock) and then Nintendo will be able to milk the living crap out of nVidia's upscaling tech.

Maybe. It could simply be more RAM, or additional vRAM compared to handheld so we could have better textures in docked mode.

Sounds cool. How would that work?

It's definitely possible to have the Switch 2 dock grant a bigger boost in performance than the Switch 1 dock. Method 1 would be to put a substantially more powerful chipset into the Switch 2 itself, but have it run severely underclocked in handheld mode to save on battery life, but then when docked and hooked up to a permanent power source, fully open up the taps on the handheld chipset and maybe build some extra fans into the dock for better cooling. Method 2 would be to put a secondary chipset into the dock itself, which can work in conjunction with the handheld Switch chipset when the handheld is docked, this is something that Nintendo has patented, but getting 2 different chipsets to run in conjunction with one another can complicate development alot (just look at Sega Saturn), so I'm not sure if Nintendo would actually go that route instead of method 1.

The main bottleneck in docked mode is the thermals, which is why the Switch's Tegra chip is severely underclocked even in that mode.

So what you would need, ideally, is beefier cooling in the Switch 2 (but do consider you have to balance the size and weight of the cooler and heatsink against kid hands and weak-ass kid's arms).

Alternatively you could include the cooling on the dock itself though external solutions like this often do not work well (most being effectively scams for clueless laptop and also X360 owners in the past).

Method 1 is very similar to what they kinda do nowadays anyway, right?

Yes they could do it but the Switch 2 would need probably a USB 4.0 speed port or something comparable to a Thunderbolt speed connection and I don't know if Nintendo will want to bite on that cost or not.

Or maybe some kind of proprietary connector.

Some laptops do this today and Macbooks of course come with Thunderbolt speed USB ports. I guess it would depend on if Nintendo believes it's something worth the extra cost or if they could get the manufacturer to supply it to them for cheap.

Yes, though they can go even further than they did on Switch 1. Switch 1 docked is only about double the handheld specs. They could in theory go with an even more expensive and powerful chipset, something like 4.5 tflops (about Xbox Series S tier) when docked but only like 1.5 tflops (about SteamDeck tier) in handheld mode. They just have to be willing to pay for a chipset that powerful and design a good docked cooling solution to make sure it doesn't overheat, some extra fans on the dock itself that feed cool air into the handheld air intake should do it.

Would likely result in the dock, being akin to how it is now + a wire that goes to the box part that holds the extra hardware.
So the dock would be a bigger thing.  Also if Nintendo spends like 100$ extra on the dock, to give it hardware (say half the GPU is in there, otherhalf inside the handheld part), and that would drive up the total packageing price for a Switch 2 by those 100$ then (might be a small price to pay to double the GPU performance).

The "easy" road, is just to make the Switch 2, the same way they did the first Switch.
The CPU+GPU just clocks up higher when docked.

Maybe the hope should be that include good active cooling in the new dock instead? so they can push cpu+gpu abit harder when docked?