In answer to your question, the Ulu shape you have is going to be prone to not running straight. The scallops of the blade will make it want to turn or twist. Many native women fear scalloped blade knives for this reason. Do I know if this is true? All I know about it has been from asking native women what they liked and disliked in a Ulu blade. I did this before I stared to make them and went around with patterns I made up and got opinions from a large number of women. It was interesting the number that had blades like the shape the one you pictured. Given to them as gifts. These were the ones they said they did not like for the reasons written above.
This is a mistake I made with my last bunch of the blades that I made. I got them way to hard, the heat treat-er I used was outside and dummy me thought it would be great having a blade that would stay sharp for ever (Not going to happen anyway) Long story short, It's going to be really hard to find a Ulu that is perfect, it really comes down to basically two blade shapes that satisfies most say 95% of the users. One is huge and used on fish most of the time has the handsaw handle to push the blade through the fish.
I have a long mental list of the do's and don'ts on the making and shaping of these blades and the handle material that has given complete satisfaction.
The funny thing about the Ulu's made from handsaw blades is that where the heat treat has no harding, they don't use that part of the blade (where the teeth are is where the temper is). Goodness I think I could write a book on this subject.
