You dont really prove why it wouldn't require a lot of research though. And I never implied that Sony would be crippled. 

How do you know PS4 owners want a Switch? If that is the case, then the PS4 and Switch are shared markets, making a PS4P pretty redundant.

Untapped portable market? Really now? 

Im sorry but a market existed for the PSP because it played games not on PS2. Same for Vita with games not on the PS3. Same for Switch with games not on the PS4. a PS4P has a market just because a portable market exists? It is about the game and unless the PS4P had games not on the PS4 (wont have) then its market appeal is actually a lot more limited than you think, at least compared to the other devices you just mentioned. 

PS5 market research is not the same as what would have to be done for the PS4P. Again, are Switch users a new market separate from the PS4? Yes/ No are both ok for a PS5, a no is not ok for a PS4P since its just a different PS4 SKU. There is some overlap, sure. But a PS5 and PS4P are going to have different research put into it. 

And as I mentioned before, all of that is part of the extensive research that will go into the device. 

Are there lots of ppl who are interested in Switch portability but PS4 games who do not own a PS4? You cant just assume this market exists or that it is even big enough to sustain a PS4P being researched, developed, marketed and distributed. 

I were playing VG since Atari when I was like 4y old... played a lot of non-kid aimed games since that age.

Sure.
I don't think people realize how inefficient the Playstation 4 SoC is. - You don't actually need a chip that is identical to the PS4 chip to achieve the same outcome.
Ergo. You don't actually need a 1.8 Teraflop chip.

The Playstation 4 chip was outclassed even on it's release, all of these years haven't exactly been kind to the Graphics Core Next 1.0 architecture or those based upon it. It's old, it's slow, it's inefficient, it's hot, it's power hungry... Vega and Polaris are significantly more energy efficient, but still pale in comparison to say Maxwell or Pascal, let alone Volta.

CPU wise, Ryzen slaps Jaguar every day of the week, throw it down on 12nm, get aggressive with binning, consolidate some other parts of the system into the SoC, lower clocks and voltages... And bobs your uncle.

And then get aggressive with battery chemistry, LiCoO2 or LiMn2O4 are good candidates or maybe even LiNiMnCoO2.
The Switch's battery is good for 4,300mAh.
4x 18650's could provide 12,000mAh.

Not my point, of course kids play games not aimed at kids, im saying if kid appropriate games ceased to exist than the kid market would drop significantly.

On that I do agree even thought my father never cared to look for kid games for me.

Well you said you were playing Atari at 4 years old so im assuming you grew up in the 80s when gaming was seen as something primarily for kids and there was significantly less games that werent suitable for children back then.

It is true, still I played MK and Carmaggedon before I was 10... and my father gifted me playboys when I was 6-8 also let me watch terror movies.

Lol i hope you're joking because that's fucked up

Care to explain why Nintendo went with a modified Tegra 1 instead of a Tegra 2 variant in the Switch?

Care to break down how much say a Vega. or Pascal / Ryzen based APU would cost compared to the current cost of the PS4's APU?

Care to mention how much "4x 18650's" cost vs the Switch's battery, how the size of the batteries compare, and if these 18650s require any additional shielding or protection circuitry to prevent portable PS4 portables from maiming their users if something goes awry?

No one's really questioning whether the technology is there. There's $1200 laptops less than an inch thick with X86 processors, and AMD GPU solutions that will eat the PS4's lunch and go dead within an hour. No one is disputing that. But now we need to make such technology less than half the size, less than half the price, and double the battery life. So please, sort out the feasibility of making such a solution less than say, $400.

Is there a reason why you are ignoring price? The person you responded to has repeatedly made it clear they arent just talking about whether or not such a device is possible but also if it can be released at a reasonable price.

Possibly because I can only go by what is happening in the general marketplace?

Besides... This entire thread is speaking in hypotheticals, which is why my stance is: You cannot gauge the pricing of a Playstation 4 Portable, but certain aspects (Battery and so on) can be improved over the Switch for minimal cost by looking at what is available on the Market.

I mean Shit. Even nVidia has better Tegra SoC's than the Switch and had them even when the Switch release.