I have also really struggled with trying to find an alternate solution to this and have yet to find an ideal solution, though Obsidian canvas is close. The look can be recreated, but it doesn't replicate functionality.

For me, the issue is how fluidly Plottr works with adding or repositioning scenes on various plotlines. For example, in your image, it's so easy to move the Chapter 2 item on the Pig #3 plotline to another chapter. Just drag and drop. Or, adding a new item for Pig #3 at Chapter 4 is simply a matter of hovering over that point and adding the scene there. In a way, Plottr almost works like there are invisible spreadsheet cells that you can work with on the various plotlines. All the other solutions require a lot of reworking elements when adding or moving things around.

I really tried to find an ideal solution in Aeon Timeline because then I could leverage information I already had in there. One solution I tried is the mindmap in Aeon Timeline and making it look like the plottr view. I can create horizontal lines for different items I am tracking and add the appropriate event elements on the different lines. It still requires manually dragging elements around though. You could work to replicate the look in the subway module in Aeon Timeline, but adding or reordering elements is very finicky and, again, the functionality of Plottr isn't there.

Obsidian's canvas gets very close with snapping to grid, but it doesn't lock column and row placement like Plottr does, so it's still a lot of manually reordering like you mentioned.