Thanks for the great feedback. Some context: Ultimate plan would have to be per account as the margins for theses new features are razor thin. $15/mo upgrade per family member seems like a reasonable compromise.
Combining all of this I think the simplest way to achieve this would be to have a "Ultimate plan features" switch on the family dashboard where the Family member can be granted these features at the cost of $15/mo.
Let's just get on the same page regarding the billing.
Suppose you get the Family plan for $20/mo and then a few days later you want to add Ultimate features for self. The easiest would probably be to pro-rate the difference until the renewal, and then the plan renews at $$35/mo.
If you paid annualy, we would also pro-rate the charge today for enabling this feature and then the entire plan would renew at joint price.
Does that sound OK?
ps. We very much appreciate the support for the product and spreading the word! 💗