I did another route summary simulation in OSPF. It covers both IPv4 and IPv6. I haven't done much with Class A or B route summary. I decided to work more on IPv6 with it.
I summarized all of Class A 10.x.x.x / FD00:10:xx::x ranges along with the Class B 172.16.x.x / FD00:172:16xx::x ranges. For fun all did all the end point routers at OSPF stubs with static routes. Check out the routing tables and databases.