The reason it’s Enter and not Space is because you can type in the text filter and navigate/play at the same time, and that’s intentional. The spacebar is needed by the text filter to split up keywords. So it doesn’t have to be Enter, but it cannot be Space, and Enter feels like the best alternative to me.
Yeah, that could work! There is a small chance that would still interrupt typing into filter for some, but perhaps it is negligeable for the convenience. Maybe Ctrl + Space could be a workaround. There is also the issue that Shift + Enter is right now used as a counterpart to force-stop playback. So a different counterpart would be needed if Shift + Space is for playing.
I mainly wanted the play button to be easy to hit, so you can spam it to preview the SFX. But holding a modifier key is not a big deal overall.