I would support the boolean tag along with the enchantment, also rarely found in dungeon chests, but more rare than others. I keep losing armor not dedicated to mobs, so those pieces being indestructible would be marvelous. However, maybe as a downside so this isn't abusable in vanilla survival, is probably make it so that armor with it doesn't count to your protection? Such as if I had an indestructible Respiration and Aqua Affinity along with an indestructible Feather Falling, they would give me my water and falling buffs, but not take effect in combat. Perhaps only additives with enchantments, and only the enchantments of those affect damage and not their default armor value? Just a thought.
I would support the boolean tag along with the enchantment, also rarely found in dungeon chests, but more rare than others. I keep losing armor not dedicated to mobs, so those pieces being indestructible would be marvelous. However, maybe as a downside so this isn't abusable in vanilla survival, is probably make it so that armor with it doesn't count to your protection? Such as if I had an indestructible Respiration and Aqua Affinity along with an indestructible Feather Falling, they would give me my water and falling buffs, but not take effect in combat. Perhaps only additives with enchantments, and only the enchantments of those affect damage and not their default armor value? Just a thought.