What i do is add the outline like you do, then press change properties, then P for prior, and make the outline whatever colour, sheet, line thickness, line style i want. Also important to press solid in the change properties dialogue if you change the thickness from 0 to anything else

Sue, your lineup is missing Perspective, and Token Treasury 2

It only works on polygons, not lines, and I think Royal Scribe has used the line tool, not the polygon ones.

First I had to cut the two areas to delete the lines joining them - which was a bit tricky. Then, I have used SIMPLIFY, with unit of 1, successfully combined the two, then fractalized with depth 40, number of times 1. The main mass is in red.

I suggest you use Glow, outside, colour 66 with appropriate blur size, and strength as 100 to give the coastline effect, rather than a separate coastline sheet. This cuts out the problem of nodes too close together.

I hope this helps.

The problem nearly certainly is far too many nodes in the big continent. Either reduce the nodes, or accept that your main continent landmass will be in 2 halves - it will still look the same as if it were one. I had the same trouble with my Myirandios world many years ago.

BTW, the best command to use to reduce nodes without totally destroying the look of your coastline is SIMPLIFY.