Colin's stem that I accidentally broke yesterday wasn't looking good today so I took it the rest of the way off. This will, of course, affect my yield in the end (31 main colas instead of 32), but I'll just have to be careful not to lose any more. Otherwise, and even including Colin, all are doing well. No yellowing leaves at present, and no apparent deficiencies.
The plants are starting to get more interesting to look at again as they grow levels and new nodes on their separate stems. As tying down will be minimal at this point (only to keep stem heights relatively level for each plant) the stems will have a chance to grow vertically. Laszlo seems to be the only plant uninterested in gaining height so I might need to continue to train him as he grows just to give each of his stems some breathing room.
Next time, I don't think I'll grow four different strains at once. It has been a learning experience so far, and has allowed me to track details for each plant on timelines for various milestones, but with each plant behaving so differently I can already see they're going to be at varying states of readiness when it comes time for me to switch to a 12/12 light cycle.