How? Left mouse click down, tiny delay, then add(!) shift to existing mouse press.

[Frasier]

I hope someone can help because I tried quite a few things, but came up empty handed.

What I need is a key to do the following.

1. Press the left mouse button.
2. Wait a tiny amount (0.1s)
3. Then add(!) the shift key to the left mouse button.
4. On release, release both shift and mouse button.

I'm using this to snap objects into place.
When in the 3rd step I use the left mouse + modifier option, it 're-clicks'. I don't want that, it just needs to add the shift to the already existing 'left mouse down'.

[Frank1]

I can not test, but maybe this works when the trigger key is pressed, maybe
Set the opposite when the key is released.

[Frasier]

Got it working. Thanks so much!