This sounds interesting. Must give it a try.There are a lot of those actually, /usr/src/tools/bsdbox,
I am new freebsd. I have created a custom image using poudriere-image following the BSD Router project guide. Added overlay files as well.I feel like I have been stating this over and over but my personal favorite is poudriere image
Compared to NanoBSD it is more flexible. LegacyBIOS is becoming extinct. Poudriere-image makes UEFI images and many many more varieties. Even ZFS support.
Same principal. Use make.conf to customize your build.
So no shooting in the dark. You need to know what you are removing and the consequences.
poudriere-image
man.freebsd.orgPoudriere image [BSD Router Project]
bsdrp.net
poudriere-image seems to be simpler compare to nanonbsd option. Is there anyway I could login to poudriere jail to make changes(such as adding users)?One that hasn't been mentionsed so far is frenzy https://frenzy.org.ua/en - that was a small version of freebsd that ran on a usb stick, similar to knoppix or DSL from the linux world. In particular they wrote some scripts that might be useful, it appears to be here on github: https://github.com/technix/frenzy Sadly it appears not to have been updated for a long time now, but it might give you some ideas.
Nanobsd is a similar idea and appears to be currently maintained https://docs.freebsd.org/en/articles/nanobsd/index.html