This is a very small QOL addon, that I came up with after accidentally hitting “SPACEBAR” too many times while i’m modeling or doing layout, with text overlays off, and not realizing i was even IN playback mode. Then everything in the interface is lagging, and making me wonder why.
So, it works as follows: If your END FRAME is greater than 0, then hitting the spacebar will start playing as normal. If the END FRAME is 0, spacebar simply does nothing.
To install, just drag in the zip. Assign to your spacebar as such:
I might be the only person who’s ever wanted this behavior, but sharing just in case there’s one more of us out there. 
nfx_playback.zip (549 Bytes)