Having an 8 hr forced timewall to maximize souls in horde is definitely very unrewarding to progression. Actually making gains after a few prestiges to get more souls per run, and higher in zone with less time required, is being completely wiped out by the fact you can't gain anything extra without arbitrarily waiting hours once you're capped on current progress.
Much like other time-gated design decisions, it makes some features neither active nor idle (neither one gives you progression), and is very very unsatisfying.
Surely there is another way this could be constructed to prevent abuse of fast prestiges being more helpful without forced waits and nothing gained?
Edit: Atm I still get ~70% of souls at 4 hr mark to reset now. Doing so 2x would still net a lot more benefit in the same time period than waiting the arbitrary 8 hr mark set to receive full gain from 1 run. Despite being more efficient, it sure feels unnecessary...