Tuning Using pellets in the slug transfer port setting

I'm just starting to shoot my M3 in .25 and I flipped my transfer port to the slug side last night to hopefully get a little more velocity with slugs at the second reg setting (or less) I am at so far. Is there any notable disadvantage in leaving it in the slug port orientation and shooting pellets from time to time? 

Also, same question with using a slug probe with pellets? 

Lastly, who makes the better slug probe: FX or NSA?



Thanks in advance.
 
The disadvantage might be that light pellets might be hard to control, meaning they will shoot to fast, and you have to readjust all the other settings on the gun. Think the purpose of the dual transfer port, is that you can shoot both pellets and slugs, wihtout having to adjust the gun to much when you switch between them. It probably depends on what power level the gun is tuned at, for slugs. If it is set for high power, you probably has to readjust both hammerspring, and valve adjuster to slow pellets down, and if it is light pellets it might be hard to get them to shoot slow enough at all. The only way to find out is to try. If you can shoot pellets by just turning the powerwheel down, it will probably work fine.