BGP - Filtering 16-/32-bit Private-ASNs in AS_PATH

Hello,
we are currently using something like

 ...
 0   chain=ixp-peer-in bgp-as-path=^6451[2-9]|645[2-9][0-9]|64[6-9][0-9][0-9]|65[0-4][0-9][0-9]|655[0-2][0-9]|6553[0-5]$ invert-match=no action=discard
 1   chain=ixp-peer-in bgp-as-path=^420[0-9][0-9][0-9][0-9][0-9][0-9][0-9]$ invert-match=no action=discard
 ...

for filtering private ASNs in AS_PATH of announcements we receive from peers. Unfortunately the regex evaluation seems to be quite resource-intensive (at least on CCR/tile), having a perceptible impact on BGP convergence time. Are there any better options?

Thanks

I believe that if you summarize your RegExp I have better performace result.
A good test site is https://regex101.com