... i dont want to recommend it, but what i have done (and is working since yrs): the orange signal pin only of RX wire of the YGE pinned out and added to one of the BEC wires. the same could be done with telemetry wire orange data pin >> E1. they are on common ground in the YGE so there should be no issue (for RS/GTR units - different story with separated RX >> potential grounding problems).
anyhow i would not recommend to anyone unless you asked YGE before about common grounding of all connectors. but like that there is no problem with connectors...
telemetry wire's red cable (rpm signal) must be pinned out anyhow and connected to middle EXT/RPM/E2 if Spirit gov is used. 1st buffer is on CH0 in my helis (including switch off via RC with the newest 4.81 release). no y-cables in my case on any of my helis - no problems with available ports even on RS unit