do results support need for boipsy?

posting this for my husband (and me)-
he is 57 & has Type 2 diabetes
annual check up showed PSA recently rising,:
1.75 5/12/25 (for context)
3.74 2/23/26,
4.91 4/3/26 (re-test)
an isoPSA was ordered with another PSA re-test in May-
3.8 PSA but isoPSA was 17.4

next step was urine test (they said it was 'ok')
(he has no symptoms of BPH)
MRI:
PSA density: 0.120
volume: 41 cubic cm and 4.9 x 4.8 x 4.0 cm
PI-RADS: 3
mild BPH (with verbiage of 'differential diagnosis also includes chronic prostatitis')
everything else on MRI in reference to cancer indicates 'no'- no lesions, tumors or enlarged nodes found.

they told us to schedule TRUS biopsy right away, they want 16 samples. In another conversation, they said they suspect something low grade that MRI didn't pick up. I asked about waiting & doing another PSA test but they said it wouldn't matter but then later sent in bloodwork orders.
If we have to proceed with biopsy, we're asking for the transperineal which carries less risk of infection. We're still doing some research but I also see other blood tests mentioned, like PHI, 4K.
In conclusion- wondering if we do 'wait & see' and what that looks like (repeat PSA every 6 mo?) or if there are other tests we should be looking into- or proceed with biopsy? Thank you