G-Suite and Office 365 backup solutions

I am looking for a backup solution for my customers who are have Google Apps or Office 365 accounts.

I have looked at StorageCraft, Veeam, Spanning, Acronis, Backupify .. but have so far rejected all of them for one or more of the following reasons:

don't support two-factor authentication on the account

don't support small businesses due to licensing model eg minimum 5 licenses

cloud only backup .. to back up cloud data a local copy is surely preferable

shared mail accounts in O365 not supported

I personally use Cloudpull software from Golden Hill but it is unfortunately G-Suite only and only for OS X, but it works well and is a one time license so very cost effective.

Does anyone have a good product to recommend?