If Erdan Worlds won't let you do what you want with the mapping, it's probably best to look around for something that will. 13th Age might be somewhat closer to that example map whose style you want to replicate, for instance as a first suggestion. You're never going to get exact matches for everything, of course (unless the source map's in a style PF already has available that is!), so you need to decide what's most important to preserve, and then work around that.

In terms of the Sheet Effects, like Edge Fade and Edge Fade Inner, or others that may help blend adjacent textures, adjusting the size and strength beyond the presets is always worth trying out. Experimentation is key though, as has been said before re Sheet Effects generally, and trying to advise you "blind" like this isn't really practical. You just need to play around with ideas and see what you think looks good. If you run into specific snags, someone here may well be able to assist.

You might also want to try varying the edges of adjacent terrains, so they're not always simple linear features - not saying to use fractals here, just add some extra curves and variations by-hand (like a weak "jigsaw piece" join, perhaps), nothing very finely-detailed. With a strong enough Effect, you'll not see much of the original shape, and it may help break-up the linear junction a bit more.

The blending in this sample map looks like it could work by adding rounded patches of one of the greens over the top of the other, with a strong Edge Fade Inner Effect on the patches Sheet, for instance.

Wasn't able to get along for yesterday's livestream, so have just been catching-up with the VOD tonight instead. SS6 looking good, and I suspect those circled key numbers especially are going to see a lot of use beyond this set alone!

However, I was shocked to see the Hobbit village didn't make everyone in chat smial 😉...

Oops, yes, I failed to spot the mountains weren't varicolor in the Alyssa Faden style - apologies for that! There is enough variety in the varicolor hills to get those to work as snow-covered mountains though, I think, particularly if you adjust the scaling separately for the X- and Y-axes (which I think you've already done anyway).

Varicolor symbols trend towards being grey or washed-out compared to the full colour versions, because of the way they're converted; I know Sue's been battling to improve this lately, though that won't help with all the older symbols. Eukalyptus' suggestion about adding "blending" polygons around the snowy hills/"mountains" is definitely worth trying; maybe in conjunction with a suitable glow around the symbols. Again, that would need experimentation to try out.

Unfortunately, and possibly because of the age of the Annual issue, the Alyssa Faden symbols don't have a "VH" = very high resolution image version, which is what's creating the "potentially blurred" issue when printing. On prints I've done, they looked OK, but I wasn't printing large areas. Certainly zooming-in to the original CC3+ map, the hills do start to look blurred. This image is a tiny extract at the normal Forum size, set at 300 dpi output resolution:

The hills definitely look "soft", though not too bad with the other symbols and labels for distractions. This may not be good enough for what you want though. The original full map is my Community Atlas "Clack Valley" one (Gallery image link).

You can create snowy hills and mountains in this style simply by choosing a suitable colour for the varicolor symbols. There is an Ice fill and an Icefield drawing tool already with CA95, so you'll just need to match the hills and mountains with that. You may need to adjust the bitmap fill scaling too, so the patterning doesn't get lost at this sort of world-level map size.

Part of the problem may be the Alyssa Faden style isn't well-suited to world-size maps, so the default scaling is set against that. As the PDF notes with CA95 note, "Alyssa's style is a great one to depict small to medium level overland maps. For very large maps, the beautiful detail of the symbols might get lost a bit." Doesn't mean you can't do it, and it will probably suit the cartoony look of the original map you'd linked to with its over-sized symbols, just that you have more effort to put in for it to work how you'd like!

Didn't somebody shoot Smaug already though? 😉🎯