Do you have a linke somewhere to your Gigamap? Because I never heard of it and it sounds really nice.
Gigamap 0.2 - Google Drive
drive.google.com
So a VT-Bam "borderpool" or something which is compatible with the current VT-BAM map?
it's based on the same source for drawing the coastlines so yes, it should line up and be compatible
then again, that depends on wherever you want lines with corners or not
as for the borderpool, it will be on a separate layer and something you'd probably deem more extreme compared to conventional borderpools i've seen here
for comparison check out the borders in gigamap, then you'll know what i mean