I just want to ask, is it possible and good to do multiple / concurrent compact at the same time with big (capacity) domains? Is there any issue with that? Or can Axigen handle the task all at the same time?
Yes, you can. It is not about Axigen handling the task but your storage supporting the huge IO pressure you will put on it.
My suggestion is to start one compact operation and see the recorded iowait values reported by top. If you are under 10% you may start another compact operation and see what iowait values you get when running with 2 simultaneously compact jobs.
From here you could “scale” but my recommendation should be to avoid this situation.
Are you concerned about the total time spent for all compact jobs if run sequentially?