Do a search again- in the strings, in the set-up and repair forum, and in the basses one. You'll find all the usual arguments boil down to these three. There's a ton of threads about this- it pops up about every three weeks. Three basic arguments appear
A. DON'T DO IT!!! IT'S HORRIBLE!! AHHH THE HUMANITY!!!
B. It's not an issue at all and fingerboard wear is a figment of peoples' imaginations- besides, Jaco used stainless rounds so you should be able to as well...
C. Use what sound good to you and count on the minimal amount of fingerboard wear as the cost of doing business.
I'm firmly in camp C. There is some wear to be expected. You can minimize it by having good technique with your left ("fretting") hand and by using nickle round wounds. Don't press any harder than you need to in order to stop the note, don't use a side-to-side vibrato, don't pluck any harder than needed, and keep your strings clean. Those things will reduce fingerboard wear to levels where while it's visible, it's not really damaging.
My first fretless fingerboard was a factory rosewood (Fender Jazz Bass Special in 1987). I used D'Addario rounds, mostly the XLS-570 stainless rounds 50-105 for about 10 years before I replaced the rosewood with ebony. And I exacerbated the wear by being too eager to buff it out with sand paper when I saw the marks the strings left. I replaced that board with a thick chunk of ebony around '96 or so and all I've ever done to that fingerboard is buff it with 0000 steel wool about once a year or less. It wore various rounds exclusively until June 2009 when I got another fretless (again with an ebony board) and put flats on the old one.
BTW, Jaco did use stainless rounds (and just about the most abrasive ones available, Rotosound RS-66) but his fingerboards were epoxy coated so it's not the same as bare wood. So using RS-66 on an inexpensive untreated rosewood board with an aggressive technique WILL result in some wear, and perhaps even extensive wear quickly. If that's the sound you want, then don't worry, just plan on replacing the board periodically. That is NOT at all a tragedy. To avoid rounds even thought they are the source of the sound you want in order to avoid wear is much like not driving your car because it will cause wear on the tires and drive train. It's a tool for creating the music, it's NOT the reason for the music.
John