I’ve had some exposure to solfege and have an understanding of how it is useful. In most of my training we used scale degree numbers. This was useful for its direct correlation to analysis, and you become familiar with how various scale degrees tend to resolve. We sang single syllables for each so seven was reduced to “sev”, etc. This has some limitations, but I use it when sightreading and it is quite helpful. When I practice I repeat phrases and passages and get out of the music early on, so by the time a performance comes, it’s familiar on a deeper level. I’ve found that when repeating a passage it takes a few times to get it just right, then if I keep repeating it goes through one more phase where it gets shaky, but if I keep going it solidifies it on a deeper level. For me technical achievement on a passage usually coincides with memorization.