The constant posting of these geese is getting a bit annoying
I use mine exactly for that, my main phone socket is not near my front room so have these going into a switch in my front room and separate router with built in VPN (y)
Irrelevant to powerline adapters. These are not 'Wifi repeaters'. A Mesh system is very good, yes, for sorting out wifi, but if you want ethernet/cat5/5e/6 somewhere (even into the back of another router for a 2nd access point!) then powerlines are good. Just don't use them in extension blocks, and if you HAVE to, don't put them in heavily used ones. The interference isn't just the manual being pedantic - makes tons of difference.
Should you be wondering, I get just under 100mbps between the same two adaptors in an apartment.
Best thing to increase coverage is a mesh system. Expensive but works and doesn’t slow your connection down to ridiculously slow speeds like these repeaters do. And with a mesh system your phone automatically connects to the strongest connection wherever you are in the house instead of for example disconnecting from your downstairs router and connecting to this one.