SoftCrossoverData?
 

I just looked in Prime95 and noticed a new line in Prime95 that says

SoftCrossoverData=34601***,1835***,1

I partially masked the numbers in case caution is necessary (like against stealing work, etc)

I tried finding info on this on Mersenne.org, mersenneforum.org, google, and of course undoc.txt and readme.txt with no success. What is this?

This is info on the current exponent you are testing. The exponent is near an FFT crossover point. Before the LL test began, prime95 ran 1000 iterations to see what the roundoff error is. If the error is below some threshold prime95 select the smaller FFT size, else the larger. This selection is written to the SoftCrossoverData entry so that prime95 remembers the FFT size chosen. You should also see some mention of this is in results.txt.