Pokemon Perfect Crystal has received a number of updates lately!

Over the past month, Pokemon Perfect Crystal, the hack that has been made to be an idealized definitive version of Pokemon Crystal that has every Pokemon available to catch and to fix a number of glaring glitches has received a number of updates!
These updates include:
Update (18/02/2019):

• Moved the 3 legendary birds to more logical locations around Johto and Kanto.

Update (24/02/2019):

• Fixed a bunch more glitches such as the Magikarp length bug, Light Ball bug and the Belly Drum glitch.

Update (01/03/2019):

• Adjusted the levels of the 3 legendary birds to have a more appropriate move set when you encounter them.
• Made all but one of the unobtainable decorations unlock upon defeating the Elite 4.
• Made the Gold Trophy unlock upon defeating Red.

Update (21/03/2019):

• Cleaned up the entrance to Cerulean Cave by extending the ledge on Route 4 over the water. This avoids a bug where your sprite disappears when you start surfing off the ledge.
• Cleaned up the added dialogue by replacing instances of “. . .” with “…” to match the rest of the game.

https://www.romhacking.net/hacks/3840/