Couple other thoughts Re: Small EC branches in transactinides. They are much easier to detect in Odd-Odd nuclei than Even-Odd for a few reasons, assuming enough decays are observed:
1. The decay following the EC of an O-O is almost always SF. This is because Rf & Sg isotopes w/ N<162 all fission at >75% branching, many very close to 100%.
2. The SF observation in O-O decay chains almost has to be from an EC daughter. The very high hinderance factors from the odd proton and neutron make direct SF decay a very unlikely observation. We would see significant SF branches in adjacent O-E nuclei before direct O-O fission would be detectable at the cross-sections currently obtainable in the Db/Bh region.
3. A negative factor in detecting small E-O EC branches is the EC daughters often have ground or excited states with similar alpha energy and lifetime as the alpha daughter. In the case of 259Sg, both it and 259Db fit this example. GARIS chain #9 above for example shows a 0.173 s 9460 keV alpha preceding the alpha assigned to 255mLr. This would be compatible with 259Sg or Db. Hence, No real way to detect any 259Sg EC branch (likely a couple of %, like the 1.3% EC branch of 261Sg) without observation of 1000+ decays (like with the 261Sg study where 1600 decays were observed), where all parents of 255Lr assigned events in the chains would be examined to see if a significant higher ratio of 9470 keV alphas occurred here as compared to the primary 255Rf->251No decay path.