When multiple axolotls attacking a mob, kill the mob that targeted by axolotls can stack the duration of regeneration effect. There is a 2 minutes limit on effect stacking in Java, but there is no limit in Bedrock.
Steps to reproduce
Create a small pool
Spawn a lot of axolotls
Summon a drowned or guardian and then kill it manually
Repeat above steps
❌ → You will get a very long duration of regeneration effect, instead of 2 minutes.
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Comments 6

When I tested this in Java last year, killing drowned one-by-one over the course of about a minute I got over 30 minutes of regeneration. If there is a 2 minute limit it must be a change or an at-a-time limit.
The stacking is probably intended so that you can get more regeneration when you have more axolotl companions. No other means of getting regeneration stacks like this.
If this issue becomes private, it can risk being unknowingly duplicated by other reports, mainly because the issue cannot be found in search results.