update on working solution (ps I added an additional monitor)
#!/bin/sh -e
#
#This script is to bypass the nvidia blues and the monitors not starting at correct size or position on reboot
sleep 5
nvidia-settings --assign CurrentMetaMode="DP-4: nvidia-auto-select +0+0 {ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}, DP-0: 1760x1440_120 +0+2160 {viewportin=2640x2160, ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}, DP-2: 3360x1440_120 +2640+2160 {viewportin=5040x2160, ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}"
giving this script "execute as a program" permissions, I can manually run this and everything gets set correctly.
Now to work out how to run this automatically on startup.
Probably not the most elegant solution but it works for me 🙂
not marking this solved yet, in case someone comes along with a better solution.