Bit late to the Party here, but I’ve played with Sub and VS Code, a comment my Son raised between the two is that Code is certainly being developed more. But that might be the fact that Sublime is a more mature.
On the point about linking assemblies the post on LinqPad is great and it works well without too much mind bending to understand.
The script editor has long been a bain. For some reason at the moment I can’t double click on text to select it all, which I am sure I could do in 9.
I don’t think there is too much value in Epicor re-inventing the wheel, as @Mark_Wonsil said but a plugin to VS-Code or Sublime would be a great value add, and much less effort. The downside is the fact that you end up relying on others maintaining the companion product. Particularly in Open Source where popularity of things tend to ebb and flow. A good example of this is good old Baseflight software for quad copters, Forks and branches all over the shop!. There could be a challenge for Epicor to keep the link up to date, if that makes sense.
An example of what I am rambling about is where websites rely on third party libraries and for some particular reason the site hosting the library is compromised, any sites using the hosted code, either stop functioning or become vunerable…I guess you could argue that proper development procedures and practices should be able to mitigate those circumstances…
I do like the Plugin idea very much.
By the way I think { should go on a new line 