You've got a forge, test some out!
I think purpose changes it significantly. I've never done any real brush clearance, but I imagine that something like the latest rambo knife would be good, with a distal taper; the blade is relatively straight which I imagine would help stop stuff glancing off at the end, and the distal taper should make it a bit quicker in the hand and easier on the wrist, forearm and elbow - I can't help but think that something tip-heavy would be pretty laborious to swing right through things, whereas if they're chopping they're hitting something significant.
I think that a similar blade profile would be useful for chopping, with the straight back making it easier to apply downward force with a batton. Ultimately though I think something like what BR showed would be better so you could skip the batton altogether
I guess there may be a tradeoff between the effort you want to exert carrying it, and the effort you want to exert using it.
Pete
All will rise again for a better day; earth, green, with waterfalls where eagles hunt their prey