Hi,
for more than a year, I have been using the mod now, and I love it. Thank you so much!
Because of that, I would like to help out where I can, and I hope you continue to develop the mod even in future versions of Minecraft!

Anyway, there seems to be a problem with the correct format for certain commands. I'm not sure if that affects other scenarios too, but here is what I found:
When trying to check for a specific item inside (in my case, a dropper) block, the format is not chosen correctly by the mod and therefore the check will not succeed. But when getting the data from the dropper that the item is in, it outputs basically the exact thing that you need to input into the command.

Here is (first) the not working command (with autocomplete) and the (second) command that is working, by just typing what the data command gave me:
1.) /execute if block 4 81 -147 minecraft:dropper{Items:[{id:"minecraft:polished_blackstone",count:20,components:{enchantments:{levels:{feather_falling:1},show_in_tooltip:false}}}]} run say Test successful!

2.) /execute if block 4 81 -147 minecraft:dropper{Items:[{id:"minecraft:polished_blackstone",count:20,components:{"minecraft:enchantments":{show_in_tooltip:0b,levels:{"minecraft:feather_falling":1}}}}]} run say Test successful!

The problem only seems to be that the "minecraft:..." is missing and it has to be in brackets. Also, "0b" can be replaced with false.

Here's a screenshot of the dropper data and the item itself:

I'm also using this version:

I hope this helps and I'm looking forward to seeing it fixed! Have a lovely day ❤️

Best regards,
luc

Thank you for these kind words.

As for the issue, it's indeed caused by namespaces. I'll try to fix it sometime in the future, as it would require NBTac to detect when it should and when it shouldn't hide namespaces. I'm also currently working on update to my other mod and generally won't have much time next month.
For now you can disable in settings hiding namespaces for both tags and string, although I know it's far from a great solution as it will affect all commands, including these that don't require namespaces.