With an anodised or polished rim-I had to take to the fitment shop-auto "no touch" changer ( about $ US10-20). Besides, anyone else notice that the tires today have stiffer sidewalls than say 15 years ago or more....or maybe I'm just getting older.
Last tire I changed in a hurry was on a 74 KTM 250 at a 45 min GP around 94-95. I had lots of help and got it done in under 10 min. Thing is, at that speed I was leary of it being on right etc. I put some Pirellis on the RM250a last year or so.
The rims were soft( I actually remembered that the stock RM rims were soft)-so I did everything you did, plus continually heated the tire. The tire on it were some name i've never heard of-and the hardest tires I ever removed, including ones I've cut off.