(moved to new topic)
Yes, you can already use relative encoders, by doing the decoding yourself with Axoloti objects.
the encoding is more a 'convention' than something that needs support as such.
simply use midi/in/cc then decode using maths logic - then you can pipe the result either directly to an object (e.g.filter) or use a mod source object.
I think adding a single object which response +/- (fraction) might be easy to add, but beyond that gets more complex, and I guess will have to compete with other enhancements (limited time etc).
remember, its unlikely that a particular controllers 'special features' will be implemented, unless there is a user out there that has the controller and feels like implementing it. the code is open source, so that is very possible and is how most open source projects get such things done. (its the only practical way)
and... if your are a programmer and want to give it a go, then you can contribute it, and it can then be merged into the main line. (of course, you can ask questions here, if you need any help doing it)
BTW: when making requests, its a good idea, to post specifics.. in this case, a link to the manual pages for the devices regarding the encoding scheme... with exact specification. I (and probably anyone else ) are far more like to look at it, if the info is close to hand... rather than being expected to find the info for ourselves (remember, we don't have the controller which already makes it a bit tricky)