Sequencing workflows based on who triggers workflow


I have a situation where I have one queue and multiple workers to execute workflows for each user on our platform. But I would like it to be such that workflows triggered by a single user would trigger sequentially while workflows triggered by different users can happen in parallel. Is there some way to affect this type of sequencing for my workflows? If not, is this type of thing possible with different queues (but I figure it would not be great to have a queue for each user on our platform or something along those lines)? Or is this possible to achieve at the activity level?

What is the maximum start rate of workflows triggered by a single user?

In a short period of time, should be relatively very small, ~5-7, at most in the worst case scenario.

Then, I would use user-id as workflow-id. Then use SignalWithStart to start (if not running) and signal workflows. Then signals will be buffered in correspondent channels. Then each workflow would process these signals one by one.