After giving the custom nameless keyboard with MX Blacks to the friend who lent it to me when my Filco arrived, my finger pains reduced actually.
I don't know about buckling springs but if you are used to a tactile typing it would be natural, but not very functional, to bottom out with the linears.
Why would you need o-rings anyway? If you pay attention to when the letters are registered on the monitor, you barely need any pressure on the keys.
My fingers started to ache with the Reds when I tried Dvorak for a few days or when I come across words I'm not familiar with, since I bottom out the keys.
When I touch type the Reds are great cause I mostly brush on the keys and the letters are registered as I go along. Hope you can adjust your typing pressure cause the Reds are great for relieving fatigue IMHO.