I tried another go at this one and was finally able to get the cracklin to pop! So I thought I would bring this one back alive on my progress.
I tried putting hot water in the bottom of the pan to prolong the cooking to achieve the Cracklin pop and it worked!
I scored and salted the fat cap liberally with kosher salt, injected, and left in the fridge for 24 hours uncovered. Removed from the fridge and used a basting brush to knock off as much kosher salt as I could, flipped over and lathered the underside and ends with a light coating of mustard, seasoned lightly all over.
Cooked at around 450F for about 50 mins until IT was 155F (wife is pregnant and didn't know how accurate my thermo was).
The result was tasty perfectly popped cracklin on top, but next time I think I will skip the additional seasoning on the fat cap, as it was a tad too salty.