A slightly different thought, if the scope of Fan's MHM increases enough when he uses Heuristic Logos Shintai to target Mass Combat units, I wonder how they interacts using MHM with Tool Transcending Constructs. Does it make it easier to build large scale infrastructure.
It's a good idea. I think though, that the anti-Chaos wards extend to the orbitals, and any daemons present have probably been kicked out by those as they probably wouldn't have very strong anchors and few or no sacrifices to give them the strength to resist the wards after thousands of years.
If we do a survey action, presumably we'd find anything interesting, so if we do it as a write-in, we can say to capture them with Ultimate Darkness Internalisation.
One thing that we're probably missing out on by the Covenant all being killed and the surface reformatted is that we don't know the names of any daemons. Otherwise we could summon them for reprocessing.
If we want to upcycle daemons, I think we need to go out and hunt them down in the Warp.
As we can't WyldShape on a macro level, we may want to do more with mass scale sorcery, which will need reagents (as well as more Paths, such as Fortune), which daemons are our best source of anyway. For example, trying to use sorcery rituals to boost the scope of Pattern Reassertion Touch to fix orbital shipyards or hulks of ships, although this may require a purchase of Wholeness Rightly Assumed.
Lastly, the way we can probably combine warp walking to reprocess daemons with WyldShaping to make orbital factories means it might be a two birds, one stone action.