Craig Rogers DVO FRAME LOCK is, indeed, a strange beast. If it works, it works really well, but half the time it’s either not working at all, or doing weird stuff… and it’s crashing a lot.
The key for me with DVO FRAME LOCK to get it to work right is to get the parameters right. I work with film sources, so whenever I can, I will use the overscanned film borders to lock onto in manual hint mode. Then you can typically tweak things with the corners setting, etc. and get it to lock down the image properly. This will work about 75% of the time, but I often will still have to manually keyframe-adjust X and Y for certain frames it didn’t catch correctly and that are “swimming.”
If you don’t have film borders, I found DVO FRAME LOCK to simply not work at all. In those cases, DVO STEADY 2 is the only option and to get that to work right often requires me to narrow down the ROI and/or switch from Auto mode to something like Center-Balanced. You have to be extremely careful with that one, though, because you find it locking down on a particular object and suddenly prevent actual camera movement, creating strange jumping artifacts.
Mind you, though, both tools could really use a full overhaul with some improved logic, less convoluted parameters and some improved algorithms that truly lock certain areas down and never allowing them to move.