I think you would prevent yourself a huge amount of mental effort and stress by just using the driver the motor manufacturer says you should be using.
From an interest and experience point of view, the experimenting is cool and great in the long run and kudos to you for your tenacity. In the short run you have a project to submit and you don't know the chance of success with your home-grown solution, which might in fact be a non-solution.
I'd be inclined to go with what the manufacturer says you should be doing, in the interests of getting your project in on time.....