I tested with bluetooth Logitech MX Master 3S and it works, however, as this is a e-ink screen, even with the Ultra-fast setting there is some laggish feeling. I would say that it is usable, but not super smooth. I have no compatible keyboard to try (no bluetooth or USB -C), but I suppose it should work too.
The built-in Onyx virtual keyboard allows for hand-writing recognition, which I use intensively.
Also, check historic of prices, it might surpirse you the increase. I would not put the price of a laptop for a e-ink tablet. Also worth to check pen tips replacement price.