in other cases with source components I did experience improved soundstage particularly in depth and instrument placement as well as additional refinement of the lower treble. So I’ve been surprised so far not to be able to experience similar improvements replacing the amplifier stock cable.
My first thought was to try a cryoed silver PC, then I realized Ice Age sells one for under $200. I’d ask them if they think their Silver-Silver PC might be worth a try given your results with their OFC cable, and if that didn’t yield positive improvements I’d just stick with the stock PC and be happy to save some $$$. FWIW.