I’m using the Mercury SRS in one of my Minis, but I’m using a Xicoy LG-15 retract/brake controller rather than the JP controller. I use the LG 15 to sequence the nose gear door, not the Mercury SRS.
I would definitely recommend using the test flight assistant to get your Mercury SRS configured, using someone else’s settings could be different depending on how you have your servo arms setup, the brand of servo etc. -Tom