IMHO every suggestion put forward here is in cloud cuckoo fantasy land.
Innovative creative ideas I am all for - but they have to have some reality base.
The surface lines lines services and timetables are what they are because they are maximised for throughput that the infrastructure can handle. Move something, you create a new problem, usually a bigger one, at the same location, or somewhere else.
It works as it is because it has to and does.
To do different needs massive infrastructure civil engineering works, grade seperation, and a lot of platform extension works. If the 4LM project had the money, I'd be pretty sure S7s would not be and we'd have all S8 - but look at the massive work that would have involved, even with selective door operation. Or S9 on the Met and S8 elsewhere.
We can't get the Picc. resignalled yet, we can't get either new trains or new signalling for the Bakerloo, Central stock really needs outright stock replacement not retractioning ~40 yr old kit, 95TS and 96TS are approaching 40 yr age with nothing on the horizon, Crossrail 2 is not even started, Farringdon City sdgs is on hold at least to 2030-2035 - - - - so where on earth does anybody think funding is going to come from for grade seperation at Aldgate or Baker/Praed or EarlsCourt, or more platforms at Baker or EdgwareRd, or different / more surface stock, et al - that you need to implement these fantasies, etc.
If there was that amount of money around, funding wholly new lines would be far more cost effective than twiddling what is there.
As has been said already, put the crayons away on this one.