GTM parameters are not preserved, or passed to GTM

Hmm, no, that’s something different.

I just found out this is an issue on stable only,
what I also found is that (on stable) some parameters are being kept, like pp, safe_mode and such. But I can’t find where these are defined or how to add to them.

On tests-passed all query parameters stay, so to summarize:

…and then I found this fix.

Is there any chance of it being backported to stable? Seems it does not have any dependencies so it should be safe.