To use hotspot in the house with more than 10 devices, I found something that works with a little money. What I end up using were some old devices that I had laying around the house. What you need are two items: a repeater, and also an old router.
If you have to use a repeater alone, use it in bridge mode so it will not be assigning new IP addresses. The IP address is assigned by the phone in that case, so you will reach its limit. On top of that, the repeater itself will take away one of the spots on your phone as one of the 10 devices.
But what I did is the following: I use the repeater which has an ethernet out and connected my phone to the repeater. Then I plugged in my old router into the repeater routers WAN port and connected it with a CAT5 cable to the repeater. Placed the old router into DHCP mode bring it with a new network name. Then I connected all the devices to the old router, and none of them show up on the repeater or on the phone's hotspot.
Basically you're creating a subnet I guess. Works great and honestly, for low bandwidth devices, it runs fine. The speed test was almost the same as off of the repeater itself. If anything, use the high priority/bandwidth devices onto the hotspot directly, and then use the repeater/router for the low bandwidth stuff (smart speakers/plugs/lights)
Also another tip I can say, right now my wireless carrier gives me an unlimited hotspot to all of my phones. I have multiple phones that come in and out of the house. So what I have done is to place all the phones with the same exact SSID for the hotspot, and also the same exact password. Therefore, the Wi-Fi repeater will join whichever phone is in the house. Personally, this has been a great replacement for the internet in my house since my demand for the internet is not that high. And if you have unlimited internet, I guess you can use this even as a replacement for home internet. Also, this way it distributes the Hotspot data usage to all the different phones.