Theres a little debug logging left in the release it seems:

8.117 Loading mod fire-place 2.1.0 (data-final-fixes.lua)
8.118 Script @fire-place/data-final-fixes.lua:9: found fuel to burn: wood (2000000)
8.118 Script @fire-place/data-final-fixes.lua:9: found fuel to burn: coal (4000000)
8.118 Script @fire-place/data-final-fixes.lua:9: found fuel to burn: solid-fuel (12000000)
8.118 Script @fire-place/data-final-fixes.lua:9: found fuel to burn: rocket-fuel (100000000)
8.118 Script @fire-place/data-final-fixes.lua:9: found fuel to burn: nuclear-fuel (1210000000)

These are left in on purpose for crash reports.

Maybe I'll remove them later. Or maybe not.