On old versions, I'd suggest disabling dual code, disabling idle skipping, using DSP LLE, and disabling DSP LLE on thread. Apparently, setting the audio backend to none also helps (according to RachelB's old thread on TASVideos.org that was a sticky until recently). However, I have never ever used anything as old as 3.0-735, so I can't guarantee that that's correct. I have no idea why a version as old as 3.0-735 would be recommended by speedrunners... If you get desyncs or any other problems on it, you're essentially on your own.
Do you actually want to record button inputs (for instance for TASing), or would a regular video be fine? If you just want a video, you should probably use something other than Dolphin's input recording.
Do you actually want to record button inputs (for instance for TASing), or would a regular video be fine? If you just want a video, you should probably use something other than Dolphin's input recording.