Leading Edges are always rounded, and Trailing Edges are always sharp or square for a reason.

The TE is cut square so the we get separation at both corners, with a stable turbulent wake in between.
The LE is rounded so that the Stagnation point (where the flow splits over/under the aerofoil) can move smoothly around the LE in firmly attached flow, without jumping due to sudden separation.

The result of both of these is that the graph of lift coefficient against angle of attack is straight, or a smooth curve, over the important portion of the graph, the bit that we use, the middle bit. That means that the behaviour of the aircraft is smooth. You might get away with a square cut LE, or a rounded TE.

But if the handling is unexpectedly lumpy, i.e. if moving a control has a small gradual effect then a sudden jump, or if the aircraft tends to waggle around, that's a sign that the TE separation point is waving around, or the LE stagnation point is jumping around, and the prime cause is a rounded TE or sharp points on the LE.

Of course you could get lucky and get away with with it.