I don’t know if this is related to the above, but I’ll mention my quick observation (take with a pinch of salt as this isn’t my area though)…
I have never used the ‘Render slices to phrase’ option myself, as I don’t use phrases. But for the shear sake of it, I did a little test.
I loaded up Renoise and set the pattern length to 48 lines, LPB 4. I then rendered out a blank track sample to the sample editor. Now the sample length is 48 lines long at LPB 4. We can get 12 beats (12*4 = 48) out of that sample/pattern length (agreed?). Now I looked at the value that is filled in next to the ‘Beatsync’ option in the sample editor. It says here 64. Hmm.
I sliced up the blank sample on the exact beats, all 12 of them. Set the render to phrase slices option to 4 LPB and finally rendered out the phrase. The result? A 64 line phrase with the beats ‘stretched’ over that many lines. Is that right, or did you expect a 48 line phrase with the trigger ‘beats’ falling exactly on each 4th line?
Did you try modifying the ‘Beatsync’ value to 48 before you selected ‘Render slices to phrase’?
Yes I did. AFAICT Renoise still gives a 64 line phrase.
I don’t know what to really make of that as I don’t use the slicing/phrases option myself. But I thought it interesting and from that I can understand why people maybe don’t understand the resulting rendered phrase…?