What would be the best treatment approach for bladder cancer patients s/p neoadjuvant therapy and surgical resection who develop oligometastatic recurrence within 1 year that is amenable to resection?

I agree with @Dr. First Last that this is a systemic disease and a "harbinger" for other micrometastasis. Data on metastasectomy is retrospective and of low level of evidence due to selection and confounding factors. I personally would not recommend local therapy with surgery or radiation, but rather prefer systemic therapy to address that concern and risk. Radiation could be given just for palliation of a metastatic site as needed. The prognosis is challenging and therapy is typically not curative in this setting. Consider clinical trials, pembrolizumab, or erdafitinib (the latter based on genomic tumor testing). Enfortumab vefotin is now FDA-approved after platinum based chemotherapy and anti-PD1/PD-L1.