Can I use OpenWrt on my Nighthawk M1 Router in order to get access to a VPN Service


I have recently acquired the Nighthawk M1 Router.
It’s a Mobile Router and therefore not Hardwired, so I can use it with my Mobile Unlimited Contract.
Yet, it has the option to have the Battery removed and to keep it running via the Charging Cable, in order to prolong the batteries lifespan.
It has pretty good hardware and therefore allows good download speeds and multiple Devices.
It’s not limited to 1 or 2 locations (like LTE for home) and can even be used in whole Europe “World Zone 1” (for about 20-40GB) so perfect for travels.

And is more Cost efficient.

However I’m afraid that tethering might be a Concern and therefore want to Install a VPN Service on this Mobile Router in order to Mask it.

So my Question to you would be?

Does the Nighthawk M1 even allow OpenWrt if a firmware were written?

Are there similar Mobile Routers that have good download-speeds and work with OpenWrt. And possibly even allow to take the battery out while using it.

Would the mobile Provider be able to see what device I’m using it’s sim card from, stationary/mobile.

Would the mobile Provider be able to see wether it’s connection is being used for tethering?

Would the mobile Provider be able to see that a friend who comes by and uses the connection with his phone? (3rd Party usage)
Or can’t he tell the difference wether it’s my or someone else’s device.

My Goal with the VPN service on the Router would be to Mask the tethering, aswell as provide a bit more security.
Would that work?
If not how can I make all devices being provided with a hotspot appear as the hotspot device itself?

I know it’s a lot of questions, but I’d really appreciate the help, haven’t found a lot online.

Hope hearing from you.

I do not see it in the table of hardware, it may not be supported:[Brand*~]=Netgear