I've been frustrated with the lack of stability in my stock jazz bass bridge so I decided to upgrade to a Babicz full contact hardware bridge. It was very straightforward - all I had to do was remove the strings, unbolt the old bridge, and install the new one. I ended up using the original screws because the ones provided with the Babicz were larger and I didn't want to drill out the holes in my bass. I would still consider this to be a direct bolt-on mod since the old screws worked fine. So far I'm very happy with it - after a few gigs none of my adjustments have changed and there is a noticeable difference in tone. I've made a video detailing the entire process and embedded it below. Hope this helps someone!