http://prntscr.com/r6jakf
Version: 1.0.19-B3

Options:
# Disable decorative sign plates (caution, hazards, etc).
B:"Without signs"=true
# Disable registration of opt'ed out blocks. That is normally not a good idea. Your choice.
B:"Without opt-out registration"=true

Hi, yes, this one is needed as creative tab icon, so its excluded from this config. As it is also not craftable, we should be fine here. Does it make a special problem in a pack?

Hi, not really, just installed a mod and noticed the config did not remove everything, though it was not intended. I guess the biggest con of it is that it still uses a block ID so in some cases it might be that 'one ID' of difference (not counting mods expanding the limit). Personally it does not bother me much, though I tried to hide it with CraftTweaker and that also did not work.

Ok, so I'll make an analog side note for 1.12 to check the item group settings for the sign, at the current stage I do not like to remove the block completely, as this would enforce admins and players to /fml confirm that a block is missing - but it should be possible to nullify the item group for the sign to get it out of the creative tab. I'll close this issue then - thanks again for the hint.

@stfwi If you are still insterested in doing something like that, it come to my mind you could do it in a non intrusive way. Thermal series mod uses a random item (I think) from the creative tab of its mod to show as an icon, which changes every n seconds. You could add an option that disables static icon (that also removes that item) and adds that kind of icon. Just a though.

Hi, already fix it ;) The version is under review on Curse and should be available in the next hours.
1.12.2 is already in maintenance release state, so I try to keep changes as small as possible there.