Should i rebuild istio envoy of each release?

recently i compiling arm64 version of isito

but about the part of istio-envoy, from 1.6.2 to 1.6.3

# 1.6.2 
9e2704aa828400b4c5e0b9c54db46c538d2b1ebf/1.14.1/Clean/RELEASE/BoringSSL
# 1.6.3 
9085616b434c0e0b54cc677cfd3b97a0fed71c0c/1.14.1/Clean/RELEASE/BoringSSL

i found the version of envoy with different commit sha.

the compiling cost too much time, (even in 8u arm host, 1h 7m 51s needed https://github.com/querycap/istio-envoy-arm64/runs/817500593?check_suite_focus=true)

What the differences of envoy between each release?
Should i rebuild istio envoy of each release?