[Quoth]

The Wacom is inferior for a portable device, big power draw. Also there is nothing wrong with either the Kobo Pen, or the MS compatible "Adrawpen" on Sage or Elipsa. An £18 Apple compatible Pencil is fine on the iPad.

I've have the Wacom EMR on a reMarkable and it's no better. I have a Wacom Bamboo and also an unknown Wacom on a Lenovo laptop/tablet convertible (64 bit).

Perhaps it's just the MS Surface that's poor?

MS bought the company than developed the current stylus they use because it's superior to the Wacom EMR. I first used a serial interface Wacom tablet in 1990s.

The Wacom EMR, MS/Kobo Pen and Apple Pencil are all pressure sensitive.

The Kobo Sage and Elipsa include Nebo software similar to the premium Nebo app (I've used it on an iPad). You can use the Nebo files on Mac, Windows, Android or IOS. Nebo needs a pressure sensitive high resolution digitiser. Only some Android models and probably all iPads since 2018.

There were phones with high resolution stylus for handwriting and drawing (and PDAs in 1990s) but the very low resolution capacitive touch Apple iPhone killed that off. There are now some models of phones with digitizers, not not eInk. One model of a phone without a stylus had LCD and an eink on rear. A failure. The only mass market for eink is reading.