Well here's a little thought:
Technically if a BPM is right, all slider ticks should land in the correct spots due to appearing on each 1/1, musically if there's an instrument that makes you start a slider on a red tick, then the music will "probably" be right for the slidertick on a red tick as well, if it's not, then there's 2 possibilities, 1) Either the slider itself doesnt fit with the music (i see people use sliders for everything instead of what their original intention is for >_>) or 2) The slider feels correct, but the tick feels out of place, then you can go ahead and silence that single slider tick so it doesnt sound out of place.
Another situation is when a whole section, doesnt feel right at all, then go ahead and ask yourself if it's because the beats seem to be landing on red ticks and sounding awkward, if that's the case you might need a metronome reset instead of a 0.5 tick rate, or is the song so soft that you cant hear any beats on 1/1? assuming the song is still at that same bpm, the sliderticks will be correct, and of course low volume on sliderticks should accompany them just like the rest of the hitsounds, otherwise you might as well use a red line to halve the bpm, if the main beat isnt really landing on a 1/1 rythm but rather a 2/1 rythm instead.
Next situation is when there's an instrument that's faster than the main beat, in this case, normally the use of tick rate 2 is correct, with the exception of swing songs, if there are sections in which said instrument isnt faster, you might consider if the instrument goes at a 1/2 rate for a considerably high enough ammount of time compared to not sounding at a 1/2 rate, and then if that's the case, you might be better off silencing some sliderticks for the softer section, otherwise might as well switch to tick rate 1 instead, in this case also all possible options from the previous situations apply, but in this case being 3/4 sliders rather than 3/2 and obv slower bpm sections on the song.
fwiw i dont see any spot where a 0.5 would fit unless you're actually doubling your bpm already, which is already wrong, and if you dont like the sound of sliderticks, just as mm201 mentioned, play with a skin that silences them, but not enforce it onto players that actually do like it.