The on-demand agent comes from the Management Gateway, which is not exactly tied to a version of LDMS. The same Management Gateway appliance works for 8.7 and 8.8. It has its own build and updates. So someday, there will probably be one, but first the MAC agent must be configured to use the Management Gateway, which as I understand it cannot yet do. Maybe next version it will be able to, but maybe not. So once that change is made, the files to do remote control through the gateway will exist, and they can be then be added to the gateway as an update.
Any word on this? I'm guessing no, but can't hurt to ask can it?
Make sure you submit a ticket for a feature request and state your level of impact. We're tired of waiting, and aren't really crazy for PC version either so we're looking into other options such as the commercial version of TeamViewer.