Good luck to you! I can comment on this decision you are making because I made the same one back in 1988 and went FT on car management, then security, then air.
1. You will feel "owned" by the company before too long if you end up in operations and that includes feeder, package, preload, hub or air. No one that I knew in management got the position that they wanted when they were promoted.
2. If you have a spouse or partner I pray that you have a strong relationship now because most spouses/partners don't understand that anyone can work such long hours. Divorces are commonplace because the spouse will not understand the level of commitment required for FT management.
3. If you are younger, in your 20s or 30s, check into the new retirement program for management NOW! It has CHANGED since I retired in 2013 and not for the better. I have heard that the starting wage for FT management has increased but management newbies are "on their own" for their retirement. No more pension for newly hired management, others are grandfathered in. Stock helps but it is not as good since the company is no longer privately held.
4. If you are younger and have an education behind you I would join FT management with the goal of it being a "resume builder." There are many companies that will still snatch you up with UPS management experience. If you don't have an education take advantage of the education benefits, I am sorry but I don't currently know what they are for management employees. I did get my MBA in 2010 using them however and paid next to nothing.
5. If you are not liked by your manager or division manager you will be SOL. You will be considered a "sub-par" supervisor and there's not much you can do about it except kiss
or try to get moved out of that position.
Best of luck to you!