OpenWRT and its LEDE fork eventually merged back together for similar reasons. I couldn't be happier -- the result is amazing.
Rick Moen wrote a good essay titled "Fear of Forking"
http://linuxmafia.com/faq/Licensing_and_Law/forking.html
It's a defense of forking, but it contains a few capsule histories of important forks of the past (from the perspective of when it was written) which are interesting.
When I first started using GNU/Linux in 1999 (Red Hat 6), I found it confusing to understand what all the fuss was about with libc/glibc and egcs/gcc. I think the differences had been resolved by that stage but all the related documentation referred to the split which made learning this strange new system very confusing (at the time, I knew what a compiler did but I didn’t know about anything about architectures other than x86 and I didn’t know why a C library was so important).
Rick includes a reference to the Emacs split of the early 90s. Jamie Zawinski’s reflection on this fork is quite interesting: https://anonym.to/?https://www.jwz.org/doc/lemacs.html (using the anoymiser as Jamie doesn't seem to like news.ycombinator.com as a referer).
Amazon [2] has some micro travel routers only - so what are good options under 100$?
[1] https://openwrt.org/toh/views/toh_available_864?dataflt%5BDe...