Way to create solid support layer BEFORE support interface? (e.g. PLA interface on top of 12% PETG supports)

[traxon 0]

I'm using a Snapmaker J1 IDEX, dual extruder. PETG in extruder 1 and PLA in extruder two. I have it building supports with PETG and then just the interface layer is PLA. However, when it extrudes PLA across the peaks of the 12% or so density PETG, it's not sticking well enough and just falling through. If there were some way to make a PETG roof on top of the 12% supports, THEN a PLA interface? That would work much better. I don't think I see a way to do this?  

[GregValiant 1,320]

A project file would be good.

You can pick the Support Extruder, and you can pick the Support Interface Extruder.  You can't mix part of the interface with the support extruder.

 

Try setting your Support Density to 20% then "Gradual Support Infill Steps" to 3, and "Gradual Support Infill Step Height" to 2mm.  The Support Infill will start out sparse but hit 20% at the top.  That would give the Support Interface more to grab on to.  I have found that the Step Height has to be sufficient because the first layer or two after a density change is like bridging.  It needs a few more layers before it develops any strength at all.

[traxon 0]

Hmm, interesting.  I've I never tried those settings. Looks like that will probably help - thanks! Except just glancing at the slice, does look like a lot of bridging in some cases. I guess it depends on the model. I'll have to try it and see. 
I'm still thinking my idea would work even better - sort of an interface for the interface. I'd like to have say 10-15% density PETG supports, then a 50% density or whatever PETG roof, then the PLA (or PVA, HIPS) interface layer. If that's not currently possible, I would think that would be a good feature to add.