@Jinmu, the tool is a part of their ColliderScribe pack, for a historical reasons (before SaaS model they used to sell these in packs).
https://astutegraphics.com/learn/update/select-like-a-pro-with-super-marquee

You can search for it at YT with an ease also:
https://youtu.be/l9QuUIK_HxQ

Some written documentation is being made although, but not published yet, AFAIK.

By default the tool works in the default 'toggle' mode and the 'boolean' mode has to be enabled, in options on on the fly with a dedicated button press.

Egor, I'm not seeing a SuperMarquee tool on Astute's website. Is this just like how I open the fridge and can't find things that are right there in front of me or do they not offer it anymore? Some of the other plugins sound great though.

Surprisingly, Affinity Designer doesn't have this either. Inkscape comes close but it only has this on a point level - not object level.

As someone mentioned earlier, any 3d/cad software did this from the dawn of time.

I know I've already commented, but I can't stress enough how much this would improve the usability of Ai. I'm surprised that more people aren't asking for this because I think about it every single time I use illustrator.

Meanwhile Astute Graphics has this Boolean mode in their SuperMarquee tool. The plugin is paid, but it exists and it works, and it provides a feedback on what is selected before the section is made. Worth trying.

this is the single most infuriating thing in illustrator.
Selecting complex patterns is impossible.
Every time I run into problems with only being able to TOGGLE the selection I go on a search for alternative software.... monopolies suck though.

I've wanted this for like 15 years. I've seen it requested over and over again. Seems like a pretty basic function that anyone who has used CAD/3D software knows is super useful. They could just make it an opt-in feature so as not to bug users who aren't familiar with it.

Would save sooo much time and frustration when you're working on something with a lot of objects or points crammed together. Also, I'm not a developer, but it seems like a relatively easy thing to implement?

It's insane that this has been missing from Illustrator for decades when Photoshop, Animate, and thousands of other platforms have it. Please add this ASAP.

Second the motion. Always use that funtion in Rhino, but wish it was in Illustrator. Sometimes I try to do most of the work in Rhino because its difficult to have precision when working in Illustrator.

I was going to post this, but found yours. But it's a very good idea - please implement it Adobe!

My original post:
----

Could we have it so SHIFT "Adds" to selection (which is current effect), but then CONTROL or COMMAND "Subtracts" from the selection?

This would be a very useful interface tweak, and it works this way in Photoshop and Cinema 4D.

For example: I have a file with many overlapping shapes/masks. I make a large marquee selection, but accidentally grab several things I don't want. I can hold SHIFT and carefully select the objects I don't want to deselect them, BUT if I miss and hit something else I don't want, it gets added to my selection.

If CONTROL or COMMAND was always a "Subtract" modifier, I could easily click on objects to remove them from the current selection without worrying about it.