Specific settings when printing above support interface

[Trapperdude]

I am using HIPS as support for PETG-CF on the Prusa XL and the performance of this combination is relatively spotty. On small cross sections it fails, but on larger ones it succeeds. I am using solid interfaces with no gap. There are a number of settings I could change to solve my problem but they are impractical in practice without more specific settings being made available.

I would like to see the ability to change a number of parameters specifically for the part's half of a support interface (and maybe the support side too). Put simply, the ability to change speed, extrusion multiplier coefficient, cooling, and temperature when printing on an interface would solve my issue.

Changing, for example, the speed or cooling when printing onto only the interface would allow me to give the materials more time to bond at temperature without slowing down my whole print by a very considerable margin or risk warping it. A higher extrusion or lower extrusion multiplier would allow me to press harder into the interface with something like a CF filament to force a mechanical bond where a conventional chemical bond isn't enough on its own, or intentionally under-extrude that layer where I need the interface to break away more easily without allowing for a Z offset which would change my final part dimensions. Consider if I'm using ABS and my support material bonds too powerfully. I can under-extrude that layer and then use a slurry in post processing to restore that layer's density and finish without negatively impacting dimensional constraints.

There is always of course the obvious alternative of changing material combinations, but this isn't always possible or requires picking up a rather expensive roll of some fancy BVOH for example just to be able to try another material. I can also slow the whole print down if my prescribed solution at the interface is to print more slowly, but for large objects or production runs this can quickly turn south. Local modifiers offer some settings but not the whole suite. I could also manually insert g-code into lines that correspond to the support interface, but this is tedious, requires elevated knowledge, and is often infeasible due to the number of interfaces across many different layers

Maybe this should be broken up into more than one request, but I figured it was best to keep it together for context's sake.