Ok, so by SR5 RAW, reagents set the limit of spells cast
However, p. 188, FA, reagents can be used for "additional effects". I'm going to stick to raw reagents here to keep it simple!
Raw reagents (standard from SR5), can be used to also raise the limit by 1 for any magic test
So if I'm casting a Force 4 spell, does this now mean I can use 5 drams of reagents to raise the limit to 9? Instead of spending 9 reagents to set the limit? If so, this sounds like a rules change, rather than enhancement.
Also, does this mean that each reagent I use, can only do one thing (set the limit, raise the limit, or even reduce drain)? Or could I use one refined reagent to increase the limit by 5, and reduce the drain by 2?
Also, it says that the number of additional effects cannot exceed my magic rating, eg. 6. So would this mean that I can use 6 refined reagents to reduce drain?
Obviously I think it's down to the wording (as it often is in SR books).