What Suva says completes quite some part of the question.
My current advise for vocals if you really have to align a lead singer along your track is to Slave another host capable of audiotrack streaming to Renoise using ReWire.
Renoise doesn’t handle long samples well, they can only ever trigger from the beginning. With Reaper, and most other more conventional DAWs, the audio tracks will play from wherever you are in the timeline you if you want to start half way through the vocal automatically starts playing in the right place. To do this in Renoise it often makes sense to cut your take into smaller slices.
This is true, and a request of mine for some time now has been to automatically trigger long samples at the correct point regardless of whether the sample was triggered in that pattern…
My long sample work-around for 4/4 time signature is to sync-to-pattern the recordings, and keep the number of bars you record as a power of 2 - even if it means you have a few silent patterns recorded (ie, 2 or 4 or 8 or 16 patterns etc) and then trigger the sample at the start of each pattern using the “09##” effect to select the correct point in the sample. for 4 patterns worth of recording that would mean the first starts at 0900 (or leave it blank…), second at 0940, third at 0980, fourth at 09C0… if this makes sense.