Personally, Miro is my favorite collaborative whiteboard solution.
I often use it, and not so long ago... my work ask me why we can’t use your solution ?
Uh.. Problem, cloud is definively prohibed for us and at this time, you're not offering the possibility to install a on-premise Miro server who can be deployed. Many competitor offers this at a higher price and i think many company can pay for that.
I guess your teams must have already thought about it and that it may not be in your main strategy to develop the application in a client/server mode ... but if one day you do, think about me :)
An IT French Fan.