I mentioned this in my review, but now after a couple of weeks of using SD, I’d say this is for me the biggest “missing feature” in Script Debugger.
Pretty much everyday I’m thinking: hellfire, I wish I could just put these two scripts side by side and scroll through them line by line.
My workaround is to open the other script in a new window then faff about trying to clumsily resize and rearrange them so they line up as best as possible. Also, with Sierra now defaulting to making Command-N behave like Command-T, there’s an extra step involved even in doing that (i.e., tearing the tab off to make a new window).**
I appreciate this is probably too big to make it into an SD6 maintenance update, but I really hope it’s high on the list of things for SD7.
**Aside: I don’t know whether it’s a good thing or not, but in Sierra SD ends up with two tab bars, as well as the possibility of multiple windows (each with all their own Sierra tabs and SD6 tabs inside them. Looks messy and confusing to me, but then Apple have really lost the plot with regards to UI design in recent years IMO anyway).