TLDR:
Things may be removed from the pack. Stuff probably won't break when updating, but if it does, I'll do my best to note it in the changelogs and in my Discord server.

• The world generation can look a bit wacky sometimes. It comes with the territory of having several things that add new structures and biomes. It will improve over time, but it will always be an ongoing project to streamline it.
• When using Actions&Stuff resource pack on Bedrock Edition, some mob head blocks will be animated.
• On Java Edition, some entities like armor stands don't have lighting applied to them
• When joining a server on Java Edition, occasionally you may get a message saying "Internal Exception: java.lang.NullPointerException: Cannot invoke "net.minecraft.class_11980.method_744470"
  because "$$2" is null". You can ignore it and just try to join the server again. I'll get around to fixing this soon. There's currently more important things to fix.
• Some enchantments that are only supposed to be obtained by killing the Ender Dragon can be obtained from general chest loot. This will be hard/time consuming to fix as I have to track down which structures don't filter their loot tables properly Fixed as far as i can tell
• Occasionally on Java Edition seemingly random blocks will not display until rerendered.
• When leaving a singleplayer world you just created on Java Edition you won't be able to see your world in the worlds list until you restart the game
• Unplugging your mic can crash your game
• Cliff under a Tree (CliffTree) disables world types (including superflat)
• If you disconnect from a server while riding a Happy Ghast, your player data may become corrupted. To fix this, edit the player NBT and delete the Happy Ghast.
• When editing an existing world in the singleplayer worldlist, clicking save will cause the game to crash and complain about "Lock no longer valid"

I've actually been working on a pack for quite some time now called Vanilla Unlocked, which was designed for 1.21.4 Java only. A large modpack with hundreds of mods and lots of custom intercompatibility. But I've been working on it for over 6 months now as getting it to the quality I feel comfortable releasing is extremely time consuming. Having hundreds of mods work well together requires extensive programming making custom mods and datapacks. There is also a lot of research that I've put into making the pack run well, even on lower-end computers. Minecraft really slows down when many things are added to world generation likenew biomes and structures. But my friends have been wanting to play Minecraft and some of them only have Bedrock edition. So I decided to take what I've learned after all these months and apply it to somewhat of an offshoot of the project, which is what you see here. Vanilla Unlocked Crossplay uses all the configuration I've worked on, everything I've learned about what can and cannot be done server-side, niche couple thousand download gems of mods of seen, my own mods I've written to improve the game, and so much more I can't even describe to make the best experience I possibly can. I worked on my last public modpack for about a year straight to make it the best possible experience, then I worked on Vanilla Unlocked for another 6 months as an improvement to that in every way. And now I'm taking all that hard work and putting it into this, with a commitment to keep it up-to-date and add new features as much as possible.