RS485 + Absolute Encoder for Homing a 4th Axis?

I got my hands on a used 4th axis but need to put in a new servo which is fine. I have a Delta B3 750w servo and drive with absolute, multi turn encoders on the way (used, too). 
The machine will have Mesa cards but given that the 4th axis supposedly has no homing sensor (still waiting for it to arrive), I was hoping to be able to home it to the absolute encoder of the servo.
Would it be possible and not too difficult to use the RS485 from the drive into the host PC (with a USB adapter) to do the homing? AI seems to think so but I don't know how well versed it actually is in LCNC. It did however say that latency shouldn't really be an issue given that this is homing routine done at the start and not something that happens during actual machining. 

If this is not doable or takes a lot of trickery, I will try to put in a small hall effect sensor and home to that + Z-pulse. But would be nice if I didn't need to do that. 

If the drive and motors have absolute encoders and if you are not having encoder feedback to Linuxcnc, you may be able to program the drive to move to the "home" position when Linuxcnc sends it a home command. Then have send a homed signal to Linuxcnc which Linuxcnc could see as the home switch.

Linuxcnc also supports absolute encoders and if the absolute encoder position is being fed back to Linuxcnc, then homing is not necessary at all.