Probably not.
Ugh... of course not. I seem to keep running into limitations with C3 that really shouldn't be...
You can try this addon:
https://www.construct.net/en/forum/extending-construct-2/addons-29/behavior-easystar-js-96215
It works with Tilemap object, and as I understand, there size of tilemap is not limited by the layout size. There is a link to C3 version on the last page.
This does look like it could help, thanks. Thing is, I really don't like using 3rd party plugins, if possible, due to lack of support. I'll try it out, and maybe I'll just have create my own pathfinding code. I don't know what it is but I seem to keep bumping into edge-cases for C3 that need unnecessary work-arounds. It's really making think I need to switch to Unity.