Given that all of them are all powered hubs so power won’t be the issue and you have enough space to put them. How much will it impact performance, latency or other things I don’t know about? Or it will straight up kill the port if there are too many hubs?
I had a hub on my desk next to my monitor so I just ran the extension up the back of the monitor and fixed it in place near the top edge. That was enough distance (maybe 18-20in now that I think about it) to resolve the interference. If you play around a bit you might find that even 10in is enough distance. Try a USB 2 extension cable too, that’ll keep v3 signalling at a distance.