He can fine tune all he wants, the fact is the Granat paper(and all others) used with floor finishes clogs fast at first. Technique might save 1 in 5 or 10 sheets. So though great technique is very helpful, the bullet needs to be bitten for sandpaper cost or get a small 18" floor sander. The Rotex with Granat paper clogs fast when sanding polyurethane or the like, it's simply the nature of the beast.
I do this nearly every day. When I sand a preexisting floor finish I start lower, using 36 grit, even 24 grit.
And I know I will burn through up to 1 sheet per sq foot at first, If I get away sanding a 72" inlay and use 3 sheets of 24 or 36 grit I did great. If I spend 20.00 it is still worth it. Show me a faster way and I'll do it. As soon as the top hard of finish is sanded off and a 50 grit can be used the Rotex shines.
As a worst case scenario I figure that sanding a 72" inlay that has 3 coats of poly will cost me as much as 20.00 in sandpaper if I don't use my floor sander and only use my Rotex. If you can't live with that you need a floor sander.
I do use a RAS 180 that is a monster of a sander that is not available in the USA. Its dust collection is not very good and the paper is even more costly than the Rotex 150, but it cuts down the sanding time to 20% and does not clog up nearly as much. I believe its because of its power, so it blast through finish before there is a large heat build up. The RAS 180 cuts down sanding time to 20% NOT by 20%. It's a huge time saver, but if you dont know what you are doing you will dish your floor with that RAS 180 in a heart beat.
This clogging of the sandpaper on floor finishes is NOT the Rotex 150 machine itself, it's the floor finish and sandpaper.
The only reason I posted is because I want to very clear my opinion that the Festool Rotex 150 is a fantastic sander, for me the best I have ever used and I have used everything I could get my hands on to date. But sanding floor finish using the Rotex 150 and Granat definitely creates a situation where it clogs sandpaper very quickly. It's just a fact in my shop.