If you can test in lab, two epmp 130/180 what ever are connected each of them to their own cn matrix.
Cnmatrix have L3 ip address on port where epmp is connected (vlan n o vlan it doesnt matter).
So we have /30 subnet link via radio.
One of matrix is DR other is BDR.
Now shutdown radio link, both ports on matrix are UP because eth connection is UP (epmm is alive on eth side only radio link si down).
With that now we have lost ospf adj. and BDR is now DR (no hello pacekts from real DR).
After that radio link is UP and now we have two DR, original DR and new one which become DR on that link and what now?
Can you see now advantage of that?
I run this scenario on Mikrotik routers for 50$.
Small bandwidth, few megs is more than enough, it is not CPU thing for asking this feature.
Other scenario similar, redundant links with two radio links, using for two ospf p2p network typ links on matrix and have OSPF ECMP load balancing