That looks reasonably rideable compared to some lightweight builds I have seen. Wouldn’t want to do a big decent, crit circuit or cobbles on it though!
there comes a point where you have to say stop. gutting the left hand lever and fitting a downtube shifter must be pretty close to that point.
I also can't imagine that it's going to be the most comfortable of rides with the choice of contact point materials.
still, no deep dish, no disc, no fat tyres, it does look good.