"Please make sure, that the effective tire width is not any bigger than 30mm."
How old is that frame, and when are manufacturers going to get the memo?
This looks like the perfect frame for the mountains, but i'm not buying a frame that can't take 32C, too many secondary mountain roads that have bad asphalt, pot holes, gravel, debris, those annoying bars to prevent cattle from crossing roads, there's every reason to ride wide tyres. And if tiny tiny Pogacar rides 30C on gravel wide rims, well...
