I'll let go of it, but I just hope we're not obscuring the fact that 溶ける is the most common term for melting/thawing, etc. and that 解ける. while almost as common, usually is not used in the melt/thaw sense.

G n-grams:
雪が溶けた	3739
雪が解けた	3936
氷が溶けた	3180
氷が解けた	1279

解ける is very commonly used for snow and ice. I think it does belong in this entry. I note that one of my JEs (ウィズダム和英辞典) uses 解ける exclusively for snow/ice examples.
I see your point regarding the note. What I want to say is "解ける is only used for snow/ice" (as opposed to "only 解ける is used for snow/ice"). The same applies to 熔ける and 鎔ける. Does the note look odd with "only" in it?
Maybe it would be worth adding a sense (or entry-wide) element specifically for this information (as part of the upcoming upgrades to JMdict). The kokugos often have notes at the bottom of entries explaining kanji usage.

@@ -27 +27 @@
-<s_inf>熔ける, 鎔ける used for metals; 解ける for ice or snow</s_inf>
+<s_inf>熔ける, 鎔ける only used for metals; 解ける only used for ice and snow</s_inf>

No problem with the sense split, but I really wonder if adding 解ける to this entry is appropriate. 解ける/とける is in another entry with quite a different set of meanings. That entry has "to melt" as the 4th sense, but it's not in most references, and I'm struggling to find a current example. I suspect it's probably better to leave it out of this entry and just have it as a sense in 解ける/とける, perhaps with an "esp. ice or snow" note.
Also, the comment "熔ける, 鎔ける used for metals; 解ける for ice or snow" seems a little misleading, as 溶ける is the most common form used for ice and snow. All of the GG5 examples mentioning them use 溶ける and most of the 23 Tanaka sentences for this verb use 溶ける and refer to ice or snow.

gg5, prog, daij

Both daijr and daijs have 解ける for this sense. Meikyo notes: "雪や氷の場合は「解ける」とも。" Adding it to kanji field. 
Splitting into senses. Might be worth tagging sentences.

@@ -9,0 +10,3 @@
+</k_ele>
+<k_ele>
+<keb>解ける</keb>
@@ -24 +27 @@
-<s_inf>解ける is sometimes used also</s_inf>
+<s_inf>熔ける, 鎔ける used for metals; 解ける for ice or snow</s_inf>
@@ -27,0 +31,4 @@
+</sense>
+<sense>
+<pos>&v1;</pos>
+<pos>&vi;</pos>