EICAD wiring Harness, leave connected?

I wired up a db9 to USB connector for programming the pmags. .When using the EICAD computer program to change the advance shift of the B Curve, is it ok to leave the Tx & Rx & ground wire harness connected to the pmag afterward during flying? (I.e, it won't think it's a jumper in there?). I would like to leave a harness connected so I don't have to remove my lower cowl to get at the plug on the left pmag...

260+ hrs with one connected to mine and all is well.

Yes.

I had a recent conversation with Bill and he actually recommended doing this. Even mentioned installing the "jumper" for the A curve at the DB9.
Plus if you ever install the EIcomander, you can just make the harness up from the DB9's to the EIcomander!