I’ve done it with rival 1 shifters and GX derailleur to shift a Sunrace 11-46 and I’m super happy with it! Although the donor mech was a knackered force 1 which is easier than Apex 1 because the cable fin is held on with a cir-clip rather than riveted on.
Found this while searching for ways to bodge an MTB derailleur to replace my dying Apex 1. Use 11 speed GX or over in road shifters. May report back if I commit.
https://bikerumor.com/2020/02/07/how-to-hack-a-sram-road-group-with-eagle-derailleur-for-massive-budget-mullet-gearing/