Do you think they might add some resistance to to coil?
I dn't think it will increase resistance at all. If anything they will further lower resistance because of the more solid connection. One thing I have noticed with kanthal and silver over the last 6 months is that if the connection is not rock solid, the resistance will fluctuate wildly. I haves coil on my iAtty now that I can measure on the provari from 1.5 ohm to as high as 5.5 ohm. Tis should be eliminated with the crimp tubes the same way it was eliminated by using threaded rod and nuts to secure the kanthal on my hybrid mini.