Seconding to avoid Upmind for now, it’s really not production ready no matter who tries to convince you otherwise. You wait 1-2 days for support, if they even respond. The platform right now is very buggy, API is poorly documented and doesn’t work most of the time and is over 600ms per request.
I think they should offer an export process back to WHMCS or alike before you try Upmind because once you’re with Upmind they won’t let you actually access all the data of your customers to export properly.