My only though about this, in order for macros to work, and I'll go from my Cnj experience since it's my highest job, in order for a macro to work at least ON Cnj, you have to have those actions set to the AB somewhere. Example: when we HAD pro/Shell/SS I had a pre-battle buff like MOST Whm/Cnj/Priest <insert MMO class name here> my macro was set as such

/aoe on
/ac "Protect II" <t>
/wait 4
/ac "Stoneskin II" <t>
/wait 7
/ac "Shell II" <t>
/wait 4
/aoe off

Now here's why I mention this, in order for what your suggesting to occur as it is now in XIV, you would need to have Shell II Pro II and SS II somewhere on your action bar but then you wish to add that macro to the AB. That would be the loss of an additional AB slot; do you see what I mean? Macros imo have always been something you bind to a key in order to quickly use the action not having to find it on an AB and click it.

So I had those 3 spells available WAY down on my AB because I could bind that macro to a key and also run 3 separate macros for the spells as singles for as "needed" in battle. This keeps me from needing all bars available on screen and allows me the fastest access to my most important actions on AB (1).

Just some thoughts not sure if this is even useful. lol