I am learning at the moment a Sonata by Scarlattiand I get “stuck” with the baroque trills whilst playing the Sonata.My trills sound much too slow and much too “stilted”.
You should not strive for speed. The baroque era trills are not about that, they should be clear and musical and it often seems very suitable to vary your speed in Scarlatti's trills. Play slow enough to do them well. The "as fast as possible and must be even" trills came in the later periods.
The Sonata I am learning at the moment is froman “Introduction to Scarlatti for Beginners” and is a very easy version of the Sonata in F minor Kk466, which is my favourite at the moment.I understand this “Introduction to Scarlatti for Beginners” as an encouragement to develop from there.