Melting temperature of ABS is about twice the temperature water boils at, so I don’t think melting is much of a concern.
My suggestion would be to just bend the stab wire to accommodate the warped spacebar, as opposed to straightening the spacebar to match a straight wire. The stakes with bending/un-bending the wire are way lower than with heating and straightening a spacebar. If a warped spacebar doesn’t bother you aesthetically then bending the wire should achieve the same ends. My thinking is that the stab ticking that results from a warped spacebar is a matter of the parts of the system not moving in sync, everything being straight minimizes the likeliness of this happening but I think everything being the “same amount of bent” would work well enough.