Can confirm I was able to use Serilog on DXP. If it is officially supported, however, I'm not sure
The Foundation project uses Serilog: https://github.com/episerver/Foundation/blob/main/src/Foundation/Program.cs
We have also used it on DXP sites without any (known) problems. 🙂
Do you think making the log file json (Structure logging) would be an issue? Might just need to test.
Set it up so that you log to Application Insights. No need to write to log files.
I see blog posts about plugging in additional logging with Optimizely 12, for example with Serilog. Is this supported on a DXP hosted site?