The biggest pain point with macOS spaces is how it handles multiple windows of the same app. It drives me crazy.
What is FlashSpace’s approach for solving this?
Could you explain what you mean? The app only allows assigning the whole app to a specific workspace. So you can't have one window of the same app in workspace A and another in workspace B. It's done this way because it's the most efficient way so far, but of course I understand that sometimes people may want to have multiple windows in different workspaces. I'm going to investigate a possibility to manage apps on a window-level basis. But macOS is the limitation here, if it's slow then my hands are tied.
Not OP, but the way I use macOS Spaces is to differentiate between work and private. I use Chrome for both, so I have some Chrome windows in my work space, and some in my private space. I do similar things for other apps like iTerm. It's an important feature. I once tried having two different browsers for work/private, but it was a chore to manage which browser I opened links in, so I gave up.
My biggest problem with Spaces is that it never remembers which space anything is in. When I reboot, everything is in the wrong space and has to be moved around.
I've been using Choosy.app for easily managing different browsers for work and personal (and testing), and it works great. You set it to your default browser, and then anytime something opens a browser it pops up a picker. Lots of global and per-site configuration options like browser profile selection, private windows, etc.
I have collections of tabs in different windows and I assign those windows to different spaces. Every time I reboot Chrome all windows are assigned to whichever space is active when I launch Chrome.
I seem to recall that Chrome used to remember these assignments, so maybe it's not a macOS problem, but rather a Chrome problem...?
Btw. Zen Browser or Arc have great management of spaces in the browser. You can quickly switch between profiles without unloading them. So you can be even on a call using work space and switch to personal space. This way you don’t need to have separate windows per profile unless you need to see the content of both at the same time.
I'm of course assigning apps to specific spaces. But my browser has to be in all spaces. MacOS still doesn't remember which window is where when the app restarts or the OS reboots.
I’ve been using the Orion Browser a lot recently. Each profile pretends to be its own app as far as I can tell.
You get separated spaces for work and private and links open in the last used window. This might solve your issue of assigning multiple windows to different spaces.
Being able to have windows of the same app assigned to different spaces would be the big unlock for me to able to use your app. Not only do I do things like separate work and personal Chrome profiles (with a window open for each), frequently I'll have a Chrome window open for a specific project with tabs just for that project, so I can switch fully into that context when I want to work on something. I also frequently have sensitive tabs open that I group into a window so I don't risk oversharing something when on a Zoom call for example as I flip through my tabs.
Another example: I use Screen Sharing to manage multiple Macs on my network. Each host gets a Screen Sharing window, and I maximize each window (whose virtual resolutions are forced to my physical monitor size) and then toggle between them and other workspaces using Spaces. I need the screen real estate so I would never have multiple host windows in the same workspace.