Playing offline to avoid score being submitted means I can't use my PS4s Remote Play option in combination with OBS to capture video with an onscreen timer.

Is it acceptable to simply provide the splits.io link alongside my timerless video footage?

I don't run N++ yet I just decided to follow and I saw this post. In every other game a splits overlay isn't necessary because all that matters is how fast you completed the run and I assume it's not any different in this community. So, recording without splits should be ok :)

Splits only really matter when you're contesting world record, and even then if I can get them from your splits.io there's no problem there.