Whenever I need to color, cut, or use any tool from the top bar, the modal stays in the middle of the screen, hindering my work. Could you make it always appear on the right side, as a fixed bar, or a modal placed on the right?
What do you think?
Depends on your screen resolution. I don’t want more on the right on my 1900x1200 screen or I would have to grab it to move it to the left…
That depends largely on your screen resolution; besides, in a way, there’s already a solution: You can move the camera using the middle mouse button, also in paint mode.
Zooming is done with the mouse wheel. When you click the mouse wheel, you’re using the middle mouse button - move the camera. You can move wherever you want, left and right, up and down - and, of course, rotate and zoom. 
My screen is 1920x1080, but would it be necessary for the modal to be in the middle of the screen? It could be on the left if you wanted, or it could be a thin bar parallel to the toolbar so as not to occupy the field of view. I think it’s very important that someone observes this to change the way the slicer works.
Yes, my friend, I’m aware of those features. I’m not a beginner in the 3D world; I just noticed that this should be changed. Imagine a Photoshop where a fixed modal sits in the middle of the screen when you select a tool? That’s counterproductive.
The cutting tool example is the worst-case scenario.
The best way would for all those to be draggable anywhere we like and that they remember their position
A long, long time ago, we were recommend to place modal windows right in the centre of the screen and disable the ability to move them. The stated reason was the modal was supposed to be used to communicate some kind of urgent problem. You may remember error popups from old applications doing this.
Of course, most UI design guidelines are not worth the electricity or paper they take to store, and no-one fully follows guidelines anyway.
Irrelevant discourse over, and I quite agree with you that this window should be movable. However it should not be movable off-screen if something on it is required to continue the workflow.
I don’t know how much experience someone has when they’ve just signed up, so I try to keep my suggestions as broad as possible.
In any case, you should send a request like this directly to the developers - it’s much more likely to be seen on GitHub than here. There aren’t really any developers here; this is more of a community forum.
