Johnson has to allow a vote here, not the SNP. And Johnson has been adamant not to allow a vote on scottish independence. He's too afraid of loosing Scotland.
Also, I find it funny how you point at a poll while you argued in the past that the polls were false and didn't show the will of the people. If that was true for the brexit polls, then the same is true for the scottish independence polls, too.
The poll on the day of Brexit was 52-48 in favour of staying. Recent polls have shown it at 53 in favour of staying if there was a 2nd ref but the majority of the population is against a 2nd ref. Polls have barely moved in regards to Brexit and Scottish independence.
One thing that the polls also reflect is the fact that the way forward had not been clear. There hasn't been a poll since the election - but the ones since Johnson came to power show that the resistance against independence is waning even in the polls, something that your link also acknowledges to a degree. The difference between staying and leaving had been over 10% since May came into power, but after Johnson did so, it shrank down closer to 5%. And I'm very sure than when the Brexit finally actually happens, support will soar way above the 50%.
The poll I posted shows a 12pt lead with Boris in power.
Don't Play Stationary 4 ever. Switch!