the risks of having your money in 1 place aren’t as big as some will make out and ultimately, the much easier management and far reduced fee’s will see you achieving better returns year on year than if you spread the pot just to stay under the minimum protections (meant for situations that ‘practically’ don’t occur as governments will sooner bailout a bank than let it go bust).
The biggest reason to be spread out it usually the availability or lack thereof for certain services or share options that you wish to make use of. In this case LISA, JISA etc and shares that have yet to be added, are all reasons to have an account elsewhere, but once added here, makes sense to bring everything under a single umbrella.
worries of having your wealth in 1 pot tend to start for real when you are talking extremely large sums of money, for example you are investing hundreds of thousands up into the million+ range so it’s best to get professional advice for really large balances and appropriate money-management at that point.
I personally doubt I can reach that level of funds any sooner than 20years from now even with a miraculous 12%+ YoY return, so I am perfectly secure in having all my own finances (investment related) handled solely by T212.