Update toolchain to gcc 10.3 w/patches by earlephilhower · Pull Request #8104 · esp8266/Arduino
A project using WiFi, which before took really long to compile for any small change in the sketch, and an external lib.
With 3.0.0-17-g114a7267 : first clean build 1m:05s, second without any changes 0m:40s
With 3.0.0-19-ge8b411fa : first clean build 1m:05s, second without any changes 0m:14s
(Older octacore Windows 10 PC with HDD)
Way to go!