CaptainKraft
Rosto
mrmixer
If you've access to the customization layer you could probably implement most of your requests yourself while waiting for them to be added to 4coder.
I did some small tweaks already, but I'd rather wait for the full blown documentation before diving any deeper.
Allen has done a pretty good job with naming and making the code clear. You might be pleasantly surprised at how easy it is to pick up by simply looking through the code for customization. Also, reading others' custom files can help too
Yeah I hope what's available is a good start. API lock in is super important so I 100% understand anyone who doesn't want to go down that path before I start doing API lock in. The documentation also misses information about the structure of some systems, and the helpers and default framework are not doc'd at all, which is a problem I am not quite ready to deal with.