I don't think being an Ag pilot will work against you. It is well-documented that SkyWest wants good people who want to be here, and don't really discriminate much on background. Since any airline invests somewhere in the vicinity of $40,000 to train and type each pilot, I'd leave out the part about "trying it out" with the option of going back to your business, obviously.

Trying to guess how long you'll take to get DEN/COS and how long you'll be on reserve is like nailing Jell-O to a wall right now. No newhires have gotten DEN in a few months, right now the junior COS pilot was hired at the end of January. But, there are no reserve lines for July for DEN, so everyone gets a line, and likely will for August, too, so no infinite reserve for the near (or probably long) future for FO's there, and the outlook for transfers in looks good, as soon as they can bulk up the junior MSP/ORD/IAH domiciles (which, BTW, also currently are experiencing very short reserve times.)