Does the P3p and the p4 use the same controller?...............Now that the p4 is being discontinued I wonder if I should pick up a p4 w/out a controller since I have an extra for my P3P.

No answer? At the very least I thought the DJI Mods would respond

No you can't,they are unable to pair , and it's really unnecessary!

Apparently you can use a p3p controller with a p4. I found in a post from a few months ago.  It seems the p4 controller has 20%  less output than  a p3p controller.  The other post said he linked them and works great.  Might explain some range issues with the p4

Yes you can do,i can confirm that because i have both.

You can use a P3P/P3A RC with the P4 and vice versa, but it's not fully recommended  since the slight changes in button configuration can cause confusion. The power output from the RC could cause differences in performance.