No, it's a waste of time, 1.21.4 isn't even the latest version anymore. No point in version chasing for 2 new vanilla features when you could have thousand of mods (including backpot ones) instead. Next verison will be 1.22, I won't actively work towards splitting the modding community

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MehVahdJukaar already said it's not worth to add it to 1.21.4 and already explained why. You need to understand "no" meant "no", that's it. that's the end of the discussion.

Programming can take a lot of times. DEVs have better stuff to do than wasting their time on one older version which happened to be 1.21.4