I've seen a job that had foam injection for subsidence. It was a huge 8 bed house which had dropped in the rear middle by 6 inches including a main spine wall.
These foam systems are powerful enough to raise a house up again, they have to be careful not to overdo it.
The property developer has used the method a few times. He buys houses that have had subsidence and can't get a mortgage, gets the founds sorted then refurbished and sells.
It's certainly worth looking at, but the suitability does depend on individual circumstances. It's not a magic solution.
If the solution is a bit of underpinning, it's not that complex. Underpinning can simply mean dig a metre cube out, fill with concrete and dry pack. Then dig next section, so on. For a long wall it's possible to do mit and miss sections. It's A common solution for Victorian properties built on a spread footing maybe just on a bit of clinker.