I did it a few days ago and it’s pretty painless. Off course methods change between the 2 libraries, but with clever #define and #ifdef and #ifndef I was able to convert my code so that I can switch back and forth between FastLED and Neopixel.
I realized that the FastLED doesn’t work with the RGBW leds so I sadly can’t use that lib. I was initally wondering if it was possible, due to seeing lag on animations that were using large chunks of the strips I had (150 LEDs or so) so I was wondering if either the uController was running out of ram or steam…