My father recently had a stroke, we both have ADHD, his is untreated. Since the stroke, most of his impacts have been cognitive, not muscular and most of his cognitive issues relate to worsening executive functioning across all executive functions, but particularly exacerbating the worst issues attributed to ADHD.
As you would know ADHD is a problem with regulation, not capacity however with this stroke it appears that his capacity has fundamentally changed and is further impacted by the dysregulation.
It's still early, and we haven't seen the specialist yet but I'm taking this hypothesis to them and (if I remember to) will update/edit here with their response.
I was a CAD manager for various multi-disciplinary engineering firms in my early career, I can attest to some of the accounts regarding various CAD systems already mentioned.
One not mentioned that comes to mind is E-tap, used by electrical engineers. Well into the five figure territory once all the various bells and whistles were added.
However the most expensive software I ever saw in the wild was some little known simulation platform for a mathematician running predictive models (it also did this with 3D graphics, so both senses of the term) on mine/rail/port operational scenarios. That was into low six figures a seat and five in annual maintenance.