New Command for Mapmakers /gui

I think Mapmakers really need a new Command because Im a Mapmaker too and to make a Gui like on servers is very hard and really takes a lot of time.

The principe of the gui is like on a server (lobby selector or anything like that)

I would suggest just like the /bossbar command i would add the /gui command to add a gui type

/gui add minecraft:test then you can modify the gui /gui modify minecraft:test displayName {"text":"Text","color":"gray"} then it would be the text on top like with the Chest. Then you could even add inventory lines with /gui modify minecraft:test slots set 9 the least amount of slots are 9 like the Hotbar and the maximum is 54 like a doubble chest (you can only change the numbers with 9,18,27,36,45,54)

and then you can add with

/replaceitem gui minecraft:test inventory.0 the item you want and last but not  least

/execute if gui minecraft:test inventory.0 minecraft:air run say hi

You could then even force a player to open it like execute as Player run gui open minecraft:test (items are saved in the gui)

/gui add minecraft:test

/gui modify minecraft:test displayName/slots

/gui open minecraft:test

/replaceitem gui minecraft.test inventory.0 diamond

/execute if gui minecraft:test inventory.0 minecraft.air run say hi

This would really add so many options to mapmakers

I really wish this command will be added in 1.17 im really exited to the update :P