You're right those first 3 do look similar... I'm not surprised that I am not the first to come up with this idea though, it's been a fun project!
I just did a very (very) quick check of the first and I didn't see any reference to bullet offsets so it's possible that it runs into precision issues up close.
I also didn't notice variance in accuracy or added bullet penetration which creates an effect I'm happy with. It does however have a hitscan setting which my mod is definitely lacking.
I'll try to check all 3 of those mods properly when I have some time and might get back to you on more of the differences but you'll probably learn more just from comparing the behaviours for yourself.
I do really appreciate you bringing them to my attention though, very cool.
Scaling inaccuracy with light is a brilliant idea so if Factorio After Dark isn't compatible now then I will do my best to fix that ASAP.