As a heavy user of mouseover macros, I would like this feature to help save my macro slots. This request has been raised repeatedly in both the EN and JP communities for over a decade, yet it still hasn't been implemented.

Regarding queueing, I believe that a macro which sets a normal action to a hotbar slot can be used in the same way as usual, except that it requires a double press. I intentionally omitted <wait> in the macro below, but the drawback is that it may not function reliably at high FPS.
/action "action name" <mo>
/target <mo>
/hotbar action "action name" [#1] [#2]
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/action "action name" <mo>
/macroicon "action name"
/hotbar copy [class 1] [#1] [class 2] [#2]
/targetlastenemy