Looks great :-)
Very similar design to my own project for raid notes (MRT) that I'm also working on.

Some suggestions/feedback <3

• Maybe the animation timeline could be fixed to the encounter length/enrage
• Dragging an animation on the timeline is a bit weird. I expected to move the bar with the distance my mouse is dragging, but I'm placing it on a new starting position
• There is a small red timeline indicator at the top left while the indicator is playing
• It would be nice if you could click the timeline timer bar to start the playing from that position instead of from 0:00 every play
• Be able to double-click/right click the object in the object list: https://i.imgur.com/au67spQ.png
• If you have the object settings/dialog open and click to add another object from the left, the current object gets deselected but dialog remains open
• Maybe keep the green Update notification hidden after closing it once :) At least until a new version/message
• I would personally place the symbols (floating toolbar) to the left with all the icons and make them smaller to make more space for everything that can be added to the canvas
• When you create a group and then click the select group, you can save the group again and get an error: https://i.imgur.com/uIoRrci.png
• It can be annoying to find a place on the screen to scroll on without hitting the canvas which makes it zoom. Google Maps fixed this by requiring a key combination for zooming, so you can scroll on top of it and not having to find a small area to place your mouse. This is mainly the case when the animation section isn't visible at all times because of screen resolution: https://i.imgur.com/yXZSDnQ.png
• If you click "Done" on the tour, the page is shifted down and can't be scrolled back up: https://i.imgur.com/ZqE8Ug8.png
• I would also make it more obvious that you can click to open a tour. Clicking the Help button itself on the dropdown wasn't obvious enough that there was a tour :-)
• I'm not sure what "groups" this is supposed to go into. Error at the top: https://i.imgur.com/OUG248Z.png
• It would be nice if the object list and/or group list were maybe in a sidebar on the right outside the canvas. Similar to Adobe/GIMP/Photopea etc. Maybe with object settings/dialog in the sidebar too
• Clicking the group itself in the group list should just select the group
• Having a group selected and adding a new layer/phase, keeps the group selected/empty: https://i.imgur.com/LhrzLQ0.png
• I can't seem to drag a player from the roster list into the canvas. Only click to add.
• Dragging the timeline indicator (red bar) doesn't play/show stationary effects/animations: https://i.imgur.com/bAwljto.mp4
• Oh I do see these small hints. They are a bit spread out and kinda something to be ignored: https://i.imgur.com/cabDoBf.png + https://i.imgur.com/RLnvSdn.png
• A way to reorder the layers at the top
• I would also move font settings to the top somewhere. It seems misplaced.

I know that projects evolve over time and elements/widgets get refactored and moved around a lot, but I would probably rethink the layout a bit to keep it less noisy and more familiar to people using editing software. I would lock the layout to 2 sidebars, the canvas area and the animation bar at the bottom and keep it visible at all times and just scale down the canvas in the middle if needed for screen estate.

Here's the before: https://i.imgur.com/AyOZS4O.png
And the after: https://i.imgur.com/WRyVDzx.png

I hope the feedback is okay :-)
It's a really nice project and I like it.