Why Not Tier 1 Perks?
The change is good, but doesn't fix the problem. It'll help yes, but you're adding 9(6 for survivors) more perks. That's 18 more levels needed on a max level character. At rank 50 that's roughly almost 1mil BP at 900k. This change cuts that in half, but only at higher levels. Why not just make all perks tier 1? No one uses the lesser level perks, and most of the time they are worthless. Tier 1 perks would heavily alleviate the insane grind this game has, give people confidence to prestige, and still require a ton of playtime.
You could also add a recycler for offerings/addons that we won't use anymore. This would solve the clutter problem, let people get BP back for things they want, and also help alleviate the grind.