Serviio

Is it possible to enable/force upconversion for certain file/mime-types or bitrates?

No

Thank you for the quick reply. Is it possible to set a min bitrate as oppose to max (maxVBitrate). Or is there a place I can inject this? maxVBitrate didn't seem valid.

No you can't but what's the point? Serviio uses -sameq to ensure the result is of the same quality as the original, in terms of bitrate etc.

Something I have to check out for upconvert. I have to check out all the different switches neccessary for ffmpeg to upconvert. From my understanding, part of it is to force a higher bitrate.

Upconversion really won't help. You can't put back bits that have been taken out, and re-encoding (or transcoding) increases the compression artifacts from lossy conversion. Doing it once (or even twice) isn't so bad, but the more you do, the more the artifacts stack up. Trying to add resolution where there wasn't any helps, but you're not getting any more detail.