BP Cap with Shrine Perks QoL

So we all know how the BP count is maxed at 1,000,000 and that if you own perks that are in the current shrine you can either get 150,000 or 250,000 BP depending on the perk. So my proposal is that if you buy a perk from the shrine and you have points that are above 850,000 BP then your BP cap will go over 1 million so that you get the total amount of points you paid for. You still wouldn't be able to earn BP until it goes back to under 1 mil, but you could buy more BP from the shrine if it resets. This would make the process of buying already used perks easier so that you aren't "cheated" out of BP, but also it would let you save up more BP before an event or new chapter. What are your thoughts? I personally don't see a downside to this but idk, maybe I'm forgetting something :p