You mean
NExT2
and
SOON™
You have all the answers you need above, nothing much I can add, except I "made my own “xMagic” before they existed as a 2in1 " and they shared PO with an xM1 and and xEM and I never had any issues
I had a Spark there and moved it, to make space for those 2.
Which I subsequently moved to make way for an actual xMagic.
If you wanted to go for 3, you could probably only realistically go for an xLED and since you have an xSIID, an LF xLED might be an option
You could probably put them closer together than your picture ( as mentioned >= 5mm ) but remeber to corral them, by placing a chuppa chup stick between them and tape it down whilst the new one encapsulates.