Subliminal Talk

Would there be any extra benefits to spending more time on each stage in programs like AM, BASE, etc.? For example, would spending 64 or 96 days per stage instead of 32 be more effective long term than doing 2 or 3 runs at 32 days per stage?

No, the subs are designed to be used for 32 days per stage only. The only exception is WM which can be used for 64 days per stage but it is still not recommend. Better do 2 runs.