Agree with crankypants on all points.
It's not necessarily the case that the conversion will fail and ruin the bass, but a defang of a fretted bass should only be considered for very specific reasons.
I've done several conversions myself and I only chose to do it because the risk was worth it. A defang isn't easy and quick to do; it requires a good set of tools, materials and a lot of good ol' elbow grease. Among other things, it should only be done on a bass that has enough adjustment to deal with the missing height of the frets. Meaning at the nut, the bridge and the pickups - there has to be enough room there to accommodate the frets going bye-bye and the strings dropping by the missing fret height. It should also have a finish put on the board afterwards, for the reasons I mentioned earlier, which takes even more skill and work to do correctly.
So not only does the bass have to be chosen correctly, the work to defang it is going to cost a fortune if your luthier really knows what he's doing and is equipped to do it right.
On a first bass, then, don't even think about it

. Just get a factory FL to begin with.
L