Oh man, do ¬ go there ∨ there will be hell to pay ∧ we'll all be sorry...

It comes down to which set of symbols deserve higher priority:
1. the shifted number key symbols

£ $ % ^ &

2. the extra non-alphanumeric key symbols

# ~ \  | 

The original mapping prioritised the first set, the new mapping favours the second.

My thinking is that the second set are used more frequently (I use pipe and tilde quite a lot a but % and ^ are rarer for example) - that said symbol usage tends to vary considerably from user to user, so there's no harm in making adjustments.  Do post if that moment of clarity does manifest itself, I'm still open to interesting ideas!

It's fair enough, people have a lot of variation in their symbol usage, so custom solutions are often the best. Since I've been using the new version, the main items I need from Symbols2 are $ and _. These are both on Sym2 home row though, so it's no biggie.

By the way, I have changed my primary thumb keys - I can't see myself ever going back to traditional boards now, so I am using the ones below T/G/M/N as my primary four, and aren't using the ones below S and E much. I also got different keycaps for those keys (with a slightly lower profile too, which works well for thumb keys!)  My Atreus now looks like this: