Hello I am coming back to FastLED and…

Hello,
I am coming back to FastLED and LEDs after creating a simple project that I was happy with years ago. I want to create a FastLED based DMX slave device. This would ideally read DMX frames and switch the running pattern based on the value of a specific channel (while another channel controls the overall brightness, etc.). My issue may be one with FastLED or may be with the way I am reading DMX, but in a nutshell, I use interrupts to read incoming DMX information (after running through a MAX485 for logical translation) on the RX pin of my Arduino. I currently would like to drive SK6812 chips which rely on WS2812 timings, disabling interrupts on my board. Is there a board (one of the ARM based?) that could handle both the reading of a DMX frame (44us) and the driving of WS2812 LEDs? [Here I may be making a coding error. It takes 44us to receive each dmx channel, at which time the interrupt is raised. If my interrupt service routine finishes in < 5us would the arm based boards be able to handle the reading of DMX even though the frame is coming in across 44us?] I am not opposed to switching to a 4 wire chipset (solving my problem all together) but I am waiting patiently for the day that FastLED supports RGBW LEDs and so far I have only found them in WS2812 variants.