Having just gone thru a bunch of USB issues in the last 48 hours, I’m prompted to share my experiences.
 
I have 5 hubs hooked up to one machine. They are all 7 port hubs, and all of them have a power supply. 3 are USB 3.0 and two are USB 2.0.
 
Yes, I have a lot of USB stuff, but I don’t have 35 items. (That is, not all 7 of the ports on each hub are full. An average of 4 ports are full on each.)
 
But here is what I discovered, at least as it applies to my setup:
 
1) it pays to have -different- (brand or model) hubs all the way around. This seems to help the system keep everything straightened out, and not confuse one item with another. (Yeah: I know, it -shouldn’t- make any difference, but like the old issues with some Firewire enclosures, it does make a difference.)
 
2) individual ports each have different addresses (of course, or it would be chaos) but some >software< depends on those addresses (not just the the OS) and live plugging a device from one port to another may cause that device to stop working (being recognized.) Again, a reboot is in order, or you may need to delete, and re-add the device to the affected software.
 
3) adding a hub, or likewise moving it around, may require a reboot as well. Hubs seem to be recognized by the OS at boot time. So, plugging in a hub and getting no activity on it may simply require a reboot.
 
4) some items may be hot-pluggable and some may not be.
 
5) running a hub without an external power supply is skating on thin ice: it will work fine… until it doesn’t. (Usually fails when you really REALLY need no problems. Somebody’s Law, I think.)
 
6) Speaking of fails: hubs -will- fail, either a port at a time, or the whole bloody thing at once.
 
7) buying cheap, no-name hubs is a gamble. At the very least, read the reviews, and if you find one with strong favorables, make sure there are hundreds of them, not ten.
 
8) leave hubs plugged in, and powered on. Don’t be switching them on and off with power strip.
 
9) weirdness may happen with your computer ( not booting, for example) if a hub or something connected to it, is going out, or gone. If you experience this, try unplugging your hubs as a troubleshooting technique.
 
Brands: I like Anker products (not just their hubs, either). Amazon Basics.
Belkin is usually, but not always, good.
A good, reliable USB 3 hub will cost about $40. Yes, you can get them for less; I’m saying “don’t.”
 
As I understand it, USB hubs require one controller chip for every four ports. The good ones will have that; the cheap ones will not, and will choke when you plug in the 5th device.
  
FWIW. YMMV. HTH.