Changelog

26.3.2.1.0 - for Minecraft 26.3

Changed: speed now belongs to the harness and the pilot. This changes how existing worlds behave - read before updating.

A happy ghast is fast only while it wears a harness, ridden or parked. While it is being flown, a lead, towing, more than one player aboard, or a rider holding a ghast tear in their hotbar or offhand drops it to plain vanilla speed (1×). Ghasts without a harness are no longer permanently 2×.
New harness speeds: red, orange 2.5× - yellow, pink, magenta 2.25× - lime, green, purple 2× - white, light blue, cyan 1.75× - brown, blue, light gray 1.5× - black, gray 1.25×.
Never slower than vanilla with a harness this version stamped, in any combination. Load penalties for extra riders and towing are replaced by the plain-vanilla rule above.
Swiftness (+50% / +100%) and snowball bursts (+100% for 60 s, stacking to five minutes) are unchanged. Ceiling: 4.5×.
Upgrading: harnessed ghasts pick up the new speeds when they are mounted, or within thirty seconds of their chunk loading; ghasts without a harness return to vanilla. Going back to 2.0.x: run /function fast_happy_ghasts:admin/uninstall first, then /scoreboard players set #enabled fhg_cfg 1 once 2.0.x is installed.
Fixed: /function fast_happy_ghasts:admin/uninstall now really switches the pack off - a harnessed ghast could be sped up again by mounting, re-harnessing or feeding it after the uninstall - and it now reaches every happy ghast in loaded chunks.

First public release: every happy ghast 2×, harness colour throttle, Swiftness and snowball boosts, load penalties.