Hi, I'm doing the same, I'm stuck in 70-75 WPM, not sure if need to practice a bit more in some of the keys that are still difficult for me to type, question marks and accents (Spanish LA layout).

Guess I’ll have to improve my accuracy with my pinkies.
Also, using 2 mechanical keyboards, with different switches, I believe I do better with the one that has tactile switches, compared to Cherry MX Blue’s

As I can’t go faster, I’m trying to improve accuracy, still unable to achieve the 100 WPM goal

I've experienced those issues. At least for me, especially if stuck around 70-80 wpm, that was an issue with not being faithful to which finger is mapped to each letter. So like if you make an exception by using your ring finger for q, or your right pointer finger for t, or analogous deviations, it is probably slowing you down.

Tip 2 would be to practice typing subthreshold (not as fast as you can go) without looking at your fingers too much, and really making sure your technique is good. Plant your wrists (maybe try having them planted vs raised, whatever you prefer), really try to center over the home row. I think I recall I liked 10fastfingers for practicing before coming over to keyhero. Maybe try that.

Breath in, slow down. Start slow, and let your brain build up speed autonomously.