The modifier keys do override keys that you set by the mod, but for example, if you have the "C" key set for a mod to open up it's configuration menu by your client, and also have a command macro set to it with this mod with a modifier key, e.g. "Ctrl + C", the client will open the configuration for the mod, but won't run the command macro set by CMDKeybinds. Or, If you assign a command to something like the "W" key, then it will move the player, and run the command set by CMDKeybinds at the same time.

I'm wondering if this could be fixed so it can expand the amount of keys that can be used, regardless of how many mods you have using hotkeys.

I want to bump this issue, because I actually have the same! I'm just going to drop a comment here that I just added to the CurseForge page for the mod:

Firstly, I would like to thank you for this mod. It's a much simpler implementation than the (very) old mod that I was looking for a replacement for, but it does the job it claims to do.

I would like to request a potential feature, or perhaps a bug fix depending on how you look at it. I bind a lot of WorldEdit commands to my keys, and actually override some of my "main" keys. For example, I use [CTRL]+[W] for /ascend, so that I can quickly pop to a higher level without moving my fingers. The [W] key still functions normally as "move forward" when I am not pressing [CTRL] as a modifier, and when I do press [CTRL]+[W] together then the /ascend command executes successfully.

The issue I have is that the normal keybinding for [W] ("move forward") also executes at the same time. It would be wonderful to have an option in the macro menu for "Ignore Default Keybinds". This setting could be enabled on any defined macro, and would prevent the "normal" game keybinds from also firing after a macro is run. This would allow for a macro that is set up as "repeating" to override a normal movement or other common key when using a modifier key, without also causing the player to sprint off into the middle of nowhere.

Thanks again for the effort you put in to this mod!