If you notice a drag when you drag a mouse across an MTEX object it may be a by-product of having selection cycling turned on "slectioncycling = 2".
You can toggle this function on the fly via Ctrl+w.
Turning selection cycling off provides a smooth motion across the MTEXT object.
I have noticed better MTEXT behaves a bit more responsive with selection cycling turned off too.
Hopefully, this helps a few folks.
Best Regards
-Tim C.