As far as I know, that's basically it-- the catalog systems are mostly proc-gen, but with predetermined position and mass, and possibly an override for what the primary star type should be and some other features (to match the catalog information, of course). So anomalies are likely to occur in the sense that the mass and star choice might not match what the StellarForge might have selected otherwise, skewing it toward proprortionately more or less massive stars compared to the planetary mass. I think this is why we see a lot of planetless stars, and stars with other stars in planetary orbits, compared to what we see in non-catalog systems... if that makes sense.
Sadly, we can really only speculate based on what details have been released, and from experience in exploring these systems.
As it happens, KOI 1701 1 looks to be an example of a hand placed planet rather than some miracle of the Forge. Quite how much control they have over it remains to be seen - it might be that they give it some attributes and let forge decide what that actually produces, or they might've even decided everything about it (including that it wasn't a gas giant). But the fact it's exactly 317 EM is a big flag (oddly, EDSM has it as 316.999969 which is presumably what thet Journal says, but I'd put that down to data storage type). The other thing to note is something I saw Bravada Cadelanne point out on discord - check this. The body is supposed to be 1.69 earth radii - but has curiosly been imported as ~16900km (actually 16868.926). I'd assume this and similar bodies were imported "en masse" through a script or whatever - but it really look like someone kept messing with the mass here until they got close to what they thought the radius was for the body. In reality it should've been closer to 10,780km and nothing like 45G - but here we are
However it happened, script or manual, it does lead to the tantilizing prospect that there could be similar errors in the KOI import...