I really need to know where the quoted sentences come from to understand the context. I need more context to understand what Tom was trying to say. I don't know what Tom said versus what you are saying. I particularly don't know what you are trying to say with this:
the number of them that has ticked away (for much longer than our universe has been forming)
Is it surprising that a ten n-n-n-n-ns long DELTA-t time increment (about 10^-44 s) could be small enough to make our gigantic PMR nanoseconds seem absolutely continuous
You need context here. Just 60 frames per second makes movies and television seem continuous and the Europeans get by with on 50 frames per second as I understand. For other purposes, you need more frames per second and still more in some contexts.
This is not clear enough to me to answer other than as I did.