Hello I have a idea where if you do the command /block it will put all your ores ingots and such into a block form which would speed up the process instead of having to craft them which can take awhile. /block will easily block every item in your inventory that is possible to craft into a block.
I do think that this is a good idea, though it is not very practical especially with the new crafting book. The new crafting book allows you to shift click on the block you want to craft and it will instantly put the items into the crafting table. Using a command to do this would be a little faster, but not very practical, as the new crafting system allows you to turn items into blocks with ease.
The server is meant to be used with 1.12, though I think you can join from 1.8 plus. Most people that play on the server play in 1.12. For the people that don't play in 1.12, there must be a reason. This reason is usually mods that are not updated. An example could be your 1.11 profile has optifine and all. Either upgrade to 1.12 and update the mods, or you can simply stay in that lower version and not use the new crafting system. Implementing a new command would require a lot of work, and since the majority of the players on the server play in 1.12, implementing such a command would still be not practical. In short to those who dont play in 1.12: Tough Luck xD