I researched SFP adapter compatibility for my ISP fiber and came to the conclusion it wasn’t worth it. The copper converter they provide has to be either registered or run ISP based configs. I found one from the same brand and stats as my ONT but it was $400.
I read ISP optical networks use a lot more config to weed out gremlins and compatibility isn’t the same as copper. But it’s mostly ISP based and if they didn’t have a profile for the device, it probably wouldn’t work.
I could be wrong though or things changed since then. I’d like to have fiber straight into my router too.