Since I started this thread, I might as well mention what I’m now doing (so you can tell me not to do it!).
I use a TOI which includes an origin brush (better safe than sorry!), and targets a misc_commandmap_marker.
None of the spawn flags are set in the MCM, and the TOI has the following:
FLAGS:
AXIS_OBJECTIVE
ALLIED_OBJECTIVE
IS_OBJECTIVE
KEYS / VALUES:
track / whatever (appears when you are in the TOI)
shortname / whatever (appears on command map when you click on icon)
spawnflags / 19 (this is set from the flags above)
customaxisimage / path to whatever (axis sees this)
customalliesimage / path to whatever (allies see this)
If you wish to toggle the command map marker on and off then make a note of the targetname of the MCM, and in script:
TO SHOW:
setstate <MCM targetname> default
TO HIDE
setstate <MCM targetname> invisible
Bear in mind if you want to use custom images (or use some of the ones already in ET) that they must be SQUARE (IE both sides same length), and should ideally be power of two.
Note that not all the SD ones follow the above rules, so be wary (eg if you use the CM_TRUCK in gfx/limbo as a normal icon it’ll be distorted cos it’s the ‘wrong’ size (it’s ‘not’, since it’s actually specifically used for a TANK type of marker, which for some silly reason has different rules about it’s aspect ratio). In cases like this make your own version and make the image square to avoid it looking all squashed on your command map 