I have Windows 11 Home Edition on my Dell XPS 8940, so I don't have access to the Group Policy Editor. However, following the instructions (both the ownership/permissions change and the value change) in
https://office-watch.com/2022/force-windows-indexing-to-run-faster/
I was able to speed up indexing by at least an order of magnitude.
I have Windows 10 Home Edition on another XPS 8940, and the registry structure governing indexing appears to be the same for W10 and W11. My W10 device indexes normally without the registry change described above, so this change is a temporary work-around, not a fix. Making the registry change defeats the W11 indexing pause function. The permanent fix for the W11 slow-indexing problem lies with MS: "something" is spuriously invoking the indexing slowdown; it needs to be identified and corrected.