For non-metastatic MIBC patients with incomplete debulking TURBT, who are not surgical candidates for cystectomy or repeat TURBT, would you try chemoRT or proceed directly to systemic treatment?

Definitely chemoRT. I believe around 1/3 of patients on BC2001 had biopsy only or incomplete TURBT. No doubt maximal TURBT is preferred, but when it is not possible, that is not a contraindication to definitive treatment.

If not a chemo candidate (though there are several options), I would recommend...

Although maximal TURBT has been an essential component of trimodality therapy, it is not uncommon to see this scenario in clinical practice. Inability to maximally resect the tumor has been associated with significantly lower rates or cure, likely due to higher tumor volume and higher T stage (T3/4 ...

Would still try chemo RT in this specific scenario to give the patient the benefit of doubt. As it is non-metastatic, systemic therapy is a road to nowhere in and of itself. Need RT to give the patient a chance. Of course, need to fully discuss beforehand.