Interestingly I am still seeing this high CPU but there is no more than usual churn of routes 😞 but can't be an issue with the router as it's neighbor router is doing the same...
Basically we have 2xMX5 in one site with RPD at around 3% and the other site at over 90%.. their configs are similar and they have pretty much the same amount of routes, i.e.
MX5 with low CPU;
inet.0: 776872 destinations, 1791982 routes (776871 active, 265978 holddown, 3 hidden)
Direct: 10 routes, 9 active
Local: 7 routes, 7 active
OSPF: 10 routes, 8 active
BGP: 1791950 routes, 776842 active
Static: 4 routes, 4 active
Aggregate: 1 routes, 1 active
inet6.0: 57845 destinations, 105634 routes (57845 active, 16067 holddown, 0 hidden)
Direct: 8 routes, 8 active
Local: 12 routes, 12 active
OSPF3: 6 routes, 6 active
BGP: 105605 routes, 57816 active
Static: 2 routes, 2 active
Aggregate: 1 routes, 1 active
MX5 with high CPU;
inet.0: 776880 destinations, 2892847 routes (776872 active, 21258 holddown, 2 hidden)
Direct: 9 routes, 9 active
Local: 7 routes, 7 active
OSPF: 8 routes, 6 active
BGP: 2892819 routes, 776846 active
Static: 3 routes, 3 active
Aggregate: 1 routes, 1 active
inet6.0: 57836 destinations, 160478 routes (57836 active, 171 holddown, 2 hidden)
Direct: 8 routes, 8 active
Local: 10 routes, 10 active
OSPF3: 1 routes, 1 active
BGP: 160458 routes, 57816 active
Static: 1 routes, 1 active