I’d echo most of the comments above - I’ve been to Majorca several times for long weekend cycling trips. I’ve been based at both Puerto Soller and Pollensa, on balance I prefer the latter.
The roads are generally good, much better than the UK, but there are one or two quieter routes favoured by cyclists that are a little rougher than you’ll have been led to believe. The main climbs in the Tramentura are all fine.
There’s decent riding in the flatter half of the island as well so don’t discount that. If you want a climb that is a little different try this https://www.strava.com/segments/640925 you won’t believe how many bends and switchbacks are in the first kilometre! It finishes at a monastery that has a café.