GZDoom demo compatibility between versions

[SoulFMP]

Hello.
First of all, I'm not sure if this is the correct place to write this, so feel free to move it around if needed, or pointing me to the write place.
I usually use DoomLauncher to start my wads, and a cool feature it has is that I can record demos with it (without messing around with command lines).
I used GZDoom 4.8.2 to record all my demos in the past, but now I want to update to 4.9.0.

My question is, would 4.8.2 demos be compatible with 4.9.0, or should I keep a 4.8.2 GZD backup in case I want to watch those later down the line?

I watched a few demos and they didn't seem to desync, but all demos I watched were short levels (0:30 - 1:00 levels), so I'm not entirely sure if longer maps would desync, I'm not really savy when it comes to those things.

[wildweasel]

Whether a demo desyncs between versions or not depends entirely upon whether any of the behavior recorded in the demo has changed in the new version. It's better to assume that things will have changed, so a desync is not a matter of "if," but "when."

[SoulFMP]

So I guess the question now is, has any behaviour changed between versions? (I'm using the same .ini file, between versions, so I guess most settings would stay the same)

[Kappes Buur]

After 4.8.2, available development versions for 4.9.0 were from
g4.9pre-4 to g4.9pre-358
therefore I would assume that GZDoom has undergone some substantial changes, which would desynch any old demos, depending on the complexity of mapping features used.

My recommendation for you is to keep version 4.8.2 on your computer if you want to run the old demos reliably.

[SoulFMP]

I will keep my 4.8.2 version then, thank you very much for the help.