How to accomplish this...

I am switching over from a different membership component (and most subscriptions on PayPal)... I am going to use Stripe with MP so that users can update/cancel their own subscriptions... Here is how I envisioned handling the switch:

1) Grant all current users a temporary plan (ex. Granted 01), then manually edit their plan start & expiration date to match their current month (ex. last payment was 5/19/19, expires 6/19/19) - this means that the members next payment should happen on 6/19/19.

2) Provide an upgrade to the proper new plan so they can enter their payment information into stripe.

3) If they upgrade today (6/15/19 they should have 4? days left on the current plan)... I need EITHER of these to happen (and haven't been able to get it to work because the amounts don't make sense)

a) Either the new user upgrades to the new plan today (and is charged 125) and their next recurring payment is charged on 7/19/19 (don't think this can happen since MP cancels the current plan and the new plan is 1 month long)

b) SO, probably... if the user upgrades to the new plan today, the 4 days remaining is deducted from the 125 and they are charged (108.33?)... new plan will have start date of 6/15/19 and end date of 7/15/19. This looks like it works, EXCEPT, when I click Process Upgrade, it says that ALL payments (including recurring amounts) will be 108.33... this is wrong- a credit from a prorated amount is only a credit, not permanent discount off all payments! (see image)


Any suggestions? I also notice that with other prorated scenarios, for example if I select "Keep duration, price prorated from original plan", in the upgrade screen it shows (for example) 20.00... but when you click "Process Upgrade", the amounts on the next page's summary don't reflect this figure- in my case it just said 125 for the first month and 125 for subsequent months