Re: Mapping plan
1.4 million routes doesn't really sound like much to me for 2022. Other than the big service providers who really needs to carry the full bgp table anyway? Most folks that use BGP will probably only need a tiny fraction of it, or for the rest of us just uplink to a good service provider(in my case Internap) and let them do the routing.
I have a document here for a high end core switch from May 2004 where a vendor was using a IXIA traffic test tool against a couple of different products, once of which was capable of 1.2 million routes, though on a per port basis it was 230k. But still that was 14 years ago, and it was a switch, not even a "router"(which typically have a lot more memory).
Most companies have had to upgrade their hardware anyway just for increases in throughput.
Today I see routers at least claiming over 2M IPv4 routes and 2M IPv6 routes in hardware(vs 230k on that switch from 14 years ago) on modern equipment just on a quick search I'm sure there are others that can scale higher.