People's needs change. If the membership isn't down for a part time weekend driver position, then they can let their e board know they don't want it before negotiations start. But the company will eventually have to start providing weekend ground service, everywhere. The question is how to do that with a win-win solution. 22.4 is a mess. Getting rid of the 22.4 designation and making them all rpcd won't solve any of the operational problems with split shifts and routes. Many members nearing retirement would like an option to go part time or bid a less strenuous job to get to where they want to be. A lot of members have been getting forced into 6th punches for months on end, and they don't want it. Part Time weekend driving would address all those issues.
Let's say the company brings the idea to the table. I think I'd rather be prepared for that possibility, and look at it from all the angles ahead of time, than simply say no just because it's part time work.