Wow. this is the perfect thread. I was going to post my setup to see what others may think. After much thought as to how I could make a quick portable system without drilling a bunch of holes in my boat, this is what I came up with.
I have these rod holders mounted front and rear of the boat and decided to utilize them ( the post and mount anyway)
unscrew the holder to use the post
Notched a 2 by 6 and put a hevy metal plate on it to screw the bolt through and into the rod holder post
downriggers with swivel and quick release mounts and rod holders on plank
It takes only a couple minutes to set up and take down.