I've recently seen a new type of stepper driver board that has a solid-state rotary encoder chip fitted.  The boards fit on the back of a stepper which has to have a shaft extension, on to which is fitted a small magnet.  These encoder chips (from Broadcom for example) can have extraordinary resolution and accuracy at low price.  See for example here:

https://www.amazon.co.uk/BIGTREETECH-Closed-Driver-Control-Board/dp/B08Q3QGQ6Q

The result is a stepper-servo drive in effect, though you have to do your own "system integration".

Does anyone have experience with these please?

Yes I have played with them, not very good, very high latency, press jog and wait for it to move then wait for it to stop, The PID tuning is a real pain.

If you find different let me know what you did.

Thanks Graham - noy encouraging!  I think I'll pass...