> We want our pricing to align with the best product experience, and a flat fee would encourage marketplaces to pay out less frequently.

I don't understand how increasing pricing from a flat fee to a percentage encourages marketplaces to pay out less frequently. The cost is so nominal that it far outweighs any percentage fee.

> We don't require that they use managed accounts. Over time, I think standalone accounts will become the better option

Better for whom? [edit] My customers are not tech savvy and only want to deal with one fintech vendor, exposing Stripe to my customers seems like it's Stripe's best interest.