Your best solution would be to get batteries and a disconnect switch that meet your needs, not relying on that small jump start battery to patch a problem.
If you're worried about your truck's battery, carry a set of jumper cables to connect to your good trailer 12V system.
For the air compressor, buy wire and a connector that works with your compressor. You can also modify the compressor wires so that they reach a longer distance. Those options are all much less expense than the jump-start pack. Of course it's less convenient, taking the time and expense (a few dollars) to lengthen the wires than buying the jump pack.
For $160, I could buy two new deep cycle batteries, a disconnect switch, and the wiring to connect it all. Just saying.