No, not work. I try to explain better
I created a test multisite installation with WordPress and only the Events Manager Plugin, and i created some locations in the subsites (the locations remain in subsite). In subsite the placeholder #_LOCATIONIMAGE is ok.
But if I want to see all the locations on the main site, for example with the shortcode
[locations_list blog=0 limit=20 pagination=1]
in a page, the data locations is loaded, but #_LOCATIONIMAGE not work (the same goes for #_EVENTIMAGE).
I suppose that the problem is that: the thumbnail images remain in subsites dir and is not created the image record in the database (wp_post table)
So I've made a very bad solution: load the image in main site and create via MySQL the reference to thumb (in wp_postmeta table, records with meta_key='_thumbnail_id' )
Ps: I take this opportunity to congratulate for the great and useful plugin :)