For freeride I use adjustable ones. The longest ones I can find, think they are 28-34. The type that can be put on/removed easily without sliding over the boom ends, that do not have a long dangly pull handle but one that is attached with webbing and a small pull loop.
I don't adjust them that much after I find the length I like. I end up shifting them on the boom way more to keep them as balanced as I can get them, often while flying on foil, as it is so touchy. If it's very light I will shorten them a bit, and lengthen them a bit when it picks up.
The race lines are way easier to make longer/shorter but be careful if you get adjustable ones about how the adjustment part hangs. I think there are more options now when I bought that don't have that dangly hook on the adjustment. I've accidentally hooked the adjustment line more times than I care to remember and it's obnoxious on foil. My chinook lines were notorious for this so I replaced them with these severne ones, and I don't accidentally hook the pull loop ever. You can see the big handle that I accidentally hook in the video below.
A good example of how silly it is to hook the lines, this time on fin: