The reason some people were allowed to use it was because it wasn’t a publicly requested rule, as soon as I write something its set in stone and then there is no leniency to allow some people that would never consider abusing these tools, as soon as “one” mod is allowed then a whole bunch will then be requested.

But since I have been asked to clear this up, Schematica is NOT allowed, as it opens up pandoras box of “what else can forge run“, the issue is it uses forge; which has a substantial amount cheating “mods” that would ruin a survival server. As @mcshovel stated, no Forge, which means no Schematica.