I think most would agree that mid-pole is better than end, but slightly more complicated to set-up. I have a snuffer I might be interested in selling.
Since you have a tramp launch, do you have a separate tack line now or no? In either case you will have your halyard now running to the mouth of the snuffer, to the block at mast and back down to your halyard cleat. After that it will go to the rear of the tramp through a new block and then go forward again, at some point here it will have to go through the tramp or lacing, through the back of the snuffer bag and out of the mouth of snuffer. Your tack line can be much like it probably is and use the same block at the pole, only now it will simply pull from the mouth of the snuffer.
Here is an explanation of the patches and placement from Jake Kohl.
you typically will need three patches to gather the spinnaker in enough to fit the shorter snuffer sock. Chances are that your two existing snuffer points are not in the correct locations for the mid-pole, so you will need to add three.
1) measure the length of the sock from the grommet at the back to the aft side of the hoop (basically the area of the sock that will completely cover the spinnaker). Subtract 8 to 12 inches. This is the length the spinnaker will be when snuffed.
2) lay the spinnaker out on the ground and stake the corners
3) take two (or three) pieces of string and tie an open eye on one end (large enough to fit around your stakes).
4) mark or cut each piece of string to the measurement you took of your snuffer sock.
5) loop each piece of string around each stake/corner of the spinnaker.
6) at the bottom of the spinnaker, bring the two pieces of string together so that their ends meet, taught, from the tack and the clew. Put a piece of tape there. This is one of the snuffer points (any longer and the spinnaker will be hanging out of the sock when snuffed).
7) take the string at the head and pull it towards the mark you just made at the bottom of the kite. Put a piece of tape at the end of that string.
If the distance between these two marks is less than the snuffer distance you measured, you don't need a third grommet (but chances are you will. If the third grommet is needed, simply measure halfway between the top and bottom mark and put a third piece of tape there.
These are your snuffer points.