The workaround I'm considering is creating dummy loopbacks at the headend routers, and creating a connection under Oneclick between the DMVPN tunnels at the spoke and these dummy loopbacks.
I then track with IP SLA the reachability of these DMVPN tunnels from the headend and if a tunnel goes down I can run a simple EEM script that shuts down the associated dummy loopback for that thnnel. Oneclick will the show the live link as down since one end of the connection becomes disabled.
If reachability returns, a different EEM script will enable the associated dimmy loopback and the live link will be up.
It's not the best of workarounds, and requires upkeep, but it does work and allows the use of live links.