I found this schematic on line for a UV5R.  http://files.radioscanner.ru/files/download/file14137/shema-baofeng-5r.pdf
 
There is COR voltage along with some transistors that control the TDA-2822 audio chip. There is also a discrete volume control too. So you can get fixed de-emphasised RX audio to drive a URI. So it looks like the UV5r would be a good candidate for a node radio and long as you use the internal PL decoder which would be fine.
 
 
 
73
Jim W7RY