First and foremost, huge thanks for @pnin for allowing me to take his POCO X3 NFC index thread and shamelessly use it as a basis for this one!
Most of the guides made by X3 NFC users have been removed from here as despite the similarities of both devices, it seems like a sound idea to test them on this device beforehand. If you would like to contribute to this thread, guides on:
how to install Viper4Android
how to remove bloatware and ads from MIUI
how to disable dynamic refresh rate
and more can be found in pnin's thread linked above - let me know which one have you tested on the X3 Pro, and I will add them back to this topic with a disclaimer.
While this device is yet to finish its first month of existence on the market, and thus there is not a whole lot of custom software available yet, I thought it would be a good idea to start such a thread early. Should be much easier to update it later on, in contrary to trying to congregate everything when things truly start rolling fast.
DISCLAIMER: all credit goes to the posters; I own nothing and claim nothing (apart where otherwise stated); as usual, your device warranty is void merely by peeping beyond this point, so close your browser and run away if that's not what you intended...
Sorry for keeping the thread vastly out of date for several months. In full honesty, I've failed to find any motivation to update it, and I severely overestimated my future engagement to keeping it up to date.
With that being said, I updated the list of recoveries, and replaced the link to custom kernels and ROMs with a link to all the development threads.
If there's anything you wish to add, let me know.