[Elecraft] "random wire" and the KX3 ATU

[Jeff Herr]

I know folks who have had bad experiences using a "random" wire with an ATU.

Although I ordered a buddipole with the kx3 I still am interested in getting
A 74 foot length of wire up in the pine trees (I will have a counterpoise)
while up in the 
Lassen national forest.....we go there a lot.

When I mention this I am met with much skepticism.

Am I way off base?  Is this beyond the capabilities of the tuner?
Is there a descriptive spec for the tuner that describes the range of it
matching capability?

WW6L