As a follow-up to this issue. There was recently a fix for this issue pushed to UE5 branch. If you have UE4 github access you can see it here, basically what @_sama_24 mentioned:
https://github.com/EpicGames/UnrealEngine/commit/65ac772e9ffe514c6e2cad63425e7c5fcce1c58e
I needed this for 4.27 and so made a backport of the fix which you can find here:
https://github.com/error454/UnrealEngine/commit/2ee2ce75da917228512a520ace26e9655d7efc09
I use virtual textures for lightmaps on quest 2 (vulkan - ASTC) and everything is working perfectly with this patch.