Hi Jimmy and Welcome to the forum! You didn't say what the PIRADS scores were for the lesions identified on your mpMRI. (Lesions are graded on a 1-5 PIRADS scored by the radiologist, where scores 1 and 2 are likely not cancer, 4 and 5 likely are, and 3 is an intermediate score. As you probably know, an MRI can identify suspicious areas, but only a biopsy can diagnose prostate cancer.
I agree with Halbert -- I think it would be fine if your uro uses the MRI to guide some extra cores, even if by eye. Note that "random" cores in the different prostate zones aren't always random. A uro uses the ultrasound (US) image to aim for any suspiciously looking spot in each zone.
Abnormal prostate tissue, whether malignant or not, reflects US differently than healthy tissue and thus appears differently on the screen. While a US image can't usually distinguish abnormal from malignant tissue, and certainly not to the level of the PRIRADS scale RO's use with mpMRIs, biopsy-experienced uros are pretty good at finding cancerous lesions when they are there -- even if this is more of an "art" of shadow interpretation
I would just ensure that your uro will take a few extra cores
in the each zone with an MRI-identified lesion in addition to the typical 12 standard cores taken around the prostate.