The 2 center pins (3&4 on RJ12, 2&3 on RJ11) are the primary pair (long runs are normally twisted). The 2nd pair straddles the first at 2&5 on RJ12, 1&4 on RJ11. The 3rd pair straddles the 2nd at 1&6 on RJ12, not exist on RJ11 because only has 4 pins. If the (android/iOS) serial data link isn't needed (or not exist on some models), then RJ11 (no 3rd pair) works fine. If remote Mute & Alert aren't needed, only the center [primary] pair are used.
Remember that if viewing the plug (male) end with PINS FACING UP, the numbers go from RIGHT-2-LEFT.
** The Alert output signal may require a driver transistor to light an LED.
On the Escort 4 pin RJ11 connector, Black Ground (GND) is Pin 2 and Red +12v is Pin3.
On Uniden R4 positive and negative are reverse too.