What are you looking for an update on? There are plenty of tuned 2021s, and the cloning process is tried and true. Are you looking for something specific?
Stock turbo is good for 22psi before it's just blowing hot air. So.. 22psi at max, a little less on pump gas w/o meth.
You need 30psi to really blow that thing off, though I've seen it blown off at stock boost pressure with clamps that aren't tightened enough.
After market guagues? Sure, you can buy any guage you wire and tap it in to a sensor or harness. For mounting there are a couple companies that make A Pillar and Infotainment surrounts, p2uned also makes one for in the glove box.