Quotesquestioner Every device should really have their own tunnel. You should want finer-grained than one tunnel per-device as Android profiles provide. It doesn't have to be a separate subscription if you're not trying to mask that they're tied together from the VPN provider themselves.
I thaught of getting a second grapheneos device to use it just as a vpn/tor router.
It's more secure than most options but it's not very good at actually acting as a router. If you're using Tor, wouldn't you at least want stream isolation for each device? Why tie it all together? Doing it per-connection is much higher overhead than per-device / per-profile.
And if i am carrying around an acces point lets say for now a simcard mobile router, and i use it just for one graphene device i am enabling trivial tracking? Which anthety vould track what exactly how?
You can be tracked by the client and access point MAC addresses which remain the same while connected. The AP one is also going to remain the same even if the client cycles it per connection like GrapheneOS.
The cellular modem in the phone is also more secure than almost any external one which probably won't even get basic security patches properly and the one in the phone has good isolation. Phones are expensive so if you goal is cycling the radio hardware identifiers when changing SIMs, it wouldn't be very practical to replace the whole phone. Doesn't mean that a hotspot device is good at doing this though. It's also going to stand out compared to a phone. What's the goal?