What degree of Professional are you thinking of .. if I was cutting freehand using a jigsaw I would hope to cut within a millimetre or two. But I would be using a very good jigsaw. Sometimes that is just not accurate enough.
We are soon to be starting some cutting that can't be done by hand ..
we have just ordered one of these last week .. (6 weeks delivery)
https://ooznest.co.uk/product/workbee-cnc-full-kit/#size-colour
If you do consider a small CNC don't go with the cheapest, I know plenty people who have paid a few hundred quid and ended up with something that is close to useless, even when cutting shallow cuts in soft aluminium .