Would be nice if he gas tanks would let the comparator output based on how full they are.

I'm tempted to work on this myself (no claim implied, just it's likely a shiny will grab me instead).
Just leaving this here as an example on how to do it: https://github.com/AppliedEnergistics/Applied-Energistics-2/blob/cb56b7f6f12d4b15943e7a07deea000337d6baf3/src/main/java/appeng/block/AEBaseBlock.java#L764

I'll try to get around to this at some point if you don't - you'll probably get there first though

Some notes:

1. AE2 is LGPL now? That's awesome news, did it happen around Algorithm's retirement?
2. Funnily enough the second non-trivial thing I did with Mek was very similar. #169