The English version of this old Mac tool doesn't seem to be available anywhere so Iv'e been spending my time muddling through the Japanese. ^_^; At least I understand what these errors mean now...
The SNES and DS versions also run at different aspect ratios (but almost the same resolution). The SNES is 4:3 with non-square pixels, so the DS version looks thinner. This exaggerates the effect of the DS version’s thinner font even more.
I always felt like the DS version was harder to read; looking at them side by side, I see I wasn’t making things up! The SNES version’s font genuinely has bolder lines that are a bit easier to read.