So scaling the variable seed depth is pretty tricky. Plates can be just about any shape, which means I could be short on one continental plate and completely obliterate another with ocean. Plates that are about as wide as they are tall are ideal, while long skinny plates are a problem. Going by plate size alone won’t cut it.
I could try using plate width, though depending on which direction you are measuring that could be very short or very long if you are in a corner measuring out. Maybe if I measured in every direction(or at least 6) and then averaged it… Being in a corner would come up with a very low average, while being on the edge of a huge plate could give you a very high average. Then I could literally take a % of that average and make that the seed depth. Should allow a single sea level setting to scale to the tiniest of island plates and the largest of Pangaea continents.
Hopefully I have time on this long weekend to work it out. 