D-tuna on A string?

I just bought an EBMM axis guitar with a Floyd Rose. I’m curious if you can add the D Tuna to the A string to drop it down to G for open tunings which I use more than drop D?

If this would work, could I stack it next to the E string and have both or would they touch and only one could be used?

I haven’t found any info on this anywhere online but I can’t be the first one to think of this.