I'm suggesting exactly a visual change with no functional change to the BLM rotation, and no involvement of elemental resistances, so that you end up with (names used for familiarity)
visually Fire-focused BLM:
Fire III (nuke, immediate Astral Fire III buff) > Fire IV (nuke) > Fire IV > Fire (nuke, possible proc) > Fire IV > Fire IV > Blizzard III (weak nuke, immediate Umbral Ice III buff) > Thunder II (single target dot, possible procs) > Blizzard IV (nuke, refreshes Enochian) with possible extra instant+free Fire III and Thunder III based on procs
visually Ice-focused BLM:
Blizzard III (nuke, immediate Astral Ice III buff) > Blizzard IV (nuke) > Blizzard IV > Blizzard (nuke, possible proc) > Blizzard IV > Blizzard IV > Thunder III (weak nuke, immediate Umbral Lightning III buff) > Fire II (single target dot, possible procs) > Thunder IV (nuke, refreshes Enochian) with possible extra instant+free Blizzard III and Fire III based on procs
visually Lightning-focused BLM:
Thunder III (nuke, immediate Astral Thunder III buff) > Thunder IV (nuke) > Thunder IV > Thunder (nuke, possible proc) > Thunder IV > Thunder IV > Fire III (weak nuke, immediate Umbral Fire III buff) > Blizzard II (single target dot, possible procs) > Fire IV (nuke, refreshes Enochian) with possible extra instant+free Thunder III and Blizzard III based on procs
And AoE bits going
Fire III (single target nuke, immediate Astral Fire III buff) > Fire II (ranged AoE) > Fire II > Flare (ranged AoE) > Transpose (to Umbral Ice I) > possible Blizzard II (self AoE) or Freeze (ground target AoE) if things are about to die
v
Blizzard III (single target nuke, immediate Astral Ice III buff) > Blizzard II (ranged AoE) > Blizzard II > Freeze (ranged AoE) > Transpose (to Umbral Lightning I) > possible Thunder II (self AoE) or Burst (ground target AoE) if things are about to die
v
Thunder III (single target nuke, immediate Astral Lightning III buff) > Thunder II (ranged AoE) > Thunder II > Burst (ranged AoE) > Transpose (to Umbral Fire I) > possible Fire II (self AoE) or Flare (ground target AoE) if things are about to die
for those who just want to throw ice or lightning instead of fire.