I've never tried this, but if what people say in this thread about how PETG doesn't bond well to PLA,
Then you'll definitely need to adjust your Z-Interface distance between support and bottom layers.
The default is likely too much of a distance.
I don't know what your slicer setting is called, but in PrusaSlicer its called "Top Contact Z Distance" in the support settings, and when it comes to PLA vs PLA, it has an extra 0.17mm distance added.
My problem right now is I'm on Fedia.io and I'm liking the interface, but more and more, what used to be other instances popping up in my feed, are disappearing, and I feel like I'm missing 1/2 the content that lemmy has to offer.
That's a Dam good idea