So it's the old bow which troubles him a bit when moving towards that side. I would try to go this direction as little as possible. And look into Professional Choice SMB boots for work. And once finances allow, have the vet look at it.
My second TB had tendon damage, was sound when I first got him, but, when put into work, went lame. 6 weeks standing, bandaged, and starting out very slow after, he stayed sound. I used the SMB'S religiously.