VT (Voluntary Temp) was a great deal for commuters. It didn't affect anyone in the category you were temping to as your bid was processed after everyone who was normally in the category.

For example:
You're a NYC7ERA and an ATL7ERA temps into your category for November. If you are a blockholder (we would have called you NYC7ERB, where the B is for Block, which is equal to REG) or a RES, you will bid and be processed by PBS prior to the ATL7ERA, even if he is senior to you. In this way it didn't hurt anyone, and allowed the company to even out their staffing.

I was a commuter that lived between MSP and DTW and I would have a standing VT card in for whichever base I wasn't permanently based at. It was an equal commute to either base, and I preferred to be VT'd so the company would positive space my commute, pay for hotel, and pay per diem for the entire month (whether I was used or not)

It has to be worded just right, and I see why you're hesitant, but it really was a great deal for commuters, and like I said the rest of the guys didn't really care because the VT's always bid last.