The 160mm blade we offer to fit plunge saws was a solution created for a large UK PLC to offer to their customers to use the TS55 and similar saws for cutting 20mm and 30mm thick quartz worktops.
It's excellent in this respect and to that end we sell in the region of 9000 units a year of this particular blade.
It is actually a porcelain blade, as we found the turbo porcelain blades cut quartz far better (cleaner) than granite blades.
The issue you have is a plunge saw cuts in the opposite direction to the way a tiler would normally cut. If you're using a wet saw or grinder, they are both set up to cut down through the surface of your tile. A TS55 and similar product cut on the upstroke, so you get a lot of breakout and chipping on the surface unless you cut upside down (like you would a laminate worktop).
So for cutting worktop it's great as you're generally grinding and polishing the edge to a finish. Not something generally done with porcelain tiles.
On the question of tool damage and warranty we had a conversation with Festool about this, mainly so we wouldn't find ourselves liable for tool failure by offering a blade of this nature.
Festool Germany explained they actively market and support the TS55 for stone masonry applications on mainland Europe. Festool UK said they don't operate the same policy and would not state if this use invalidated the warranty or not. They found it difficult to deny warranty claims given the stance on this matter by the parent company in Germany.
The reality is it's less to do with the saw and more to do with extraction. As long as your plunge saw is connected to an "M" class extraction unit then you're good to go.
It's just down to you to then figure out how you're going to cut the work piece to give the desired finish.
As an aside we also sell blades for these machines that cut granite and concrete which are also used extensively in those industries.
If you have specific questions feel free to ask, I'll answer what I can.
