Large growths in gills- veins, new gill formation, or what is this? Is it a problem?

[OAE77]

 

[wolfen]

having enlarged/exposed blood vessel isn't harmful nor is it uncommon, with all three having similar issue test the water parameters and ensure adequate oxygenation, it isn't unusual for an axolotls gills to start growing in weird ways ie.. looking like antlers, horns, pig tails etc.. provided they perform their function the axolotl tends to be unaffected.