If you want a modded soil to have proper support for Soil Relocation, it must:
- Have the "Diggable" affordance.
- Have a resource item assigned to its costList.
- workToBuild should be set at 200 (if you want it to match, otherwise set it as you please).
- designatorDropdown should be set to SR (if you want it to show up in the same stack).
- designationCategory should be set to Floors if you want it to be buildable (it doesn't have to be, though).
- It should not have a driesTo, otherwise it will be considered too wet to dig.
- If you want it to be usable to fill water/wet bridgeable terrain, it must use SR.PlaceWorker_Soil.

So to be clear there are two options, you can either use SRF as a dependency in a loadfolders version of your mod or for a patch mod and do everything above or you can do a "light" compatibility where you only add a cost to the costList for your terrains and set the other stats (including designatorDropdown, just to something besides SR) that don't require SRF as a dependency.