Where do you draw the line when AI rebuilds your scan data?

I've been doing this the slow way for close to fifteen years, mostly repair work on worn castings and machined housings, and I keep the auto-reconstruction firmly in the 'starting point only' bucket. I tried one of those AI-assisted workflows on a pump housing last spring and it looked beautiful. Then I laid the result over the raw mesh and found it had cleaned up a scoured-out patch on the sealing face that turned out to be the whole reason the part was in my shop. The AI wasn't wrong about the original design, it just erased the evidence I actually needed.

I come at this from a weird corner, heritage and restoration work. Last year I scanned a carved oak fireplace surround for a client whose house burned partially, and the whole point of that job was the opposite of what most people want from these tools. The wear IS the data. Chisel marks, a split corner from some long-ago accident, uneven depths where the original carver worked fast. If I let an AI reconstruction guess the maker's intent and hand me a tidy CAD model, I'd be erasing exactly the things the client was paying me to preserve. So my rule is the raw scan is the deliverable, and any cleaned-up model lives in a seprate file labeled as my interpretation, nothing more. For the repair folks above, a straight edge means the tool did its job. For me, a suspiciously straight edge means something got erased.

Where I do use the auto tools is as a comparison trick. Run the reconstruction, then lay it over the scan and look at what moved. The spots where it deviates most are usally the hand-made details, and that's actually a handy way to find the interesting regions fast instead of hunting thru millions of points. It found chisel marks on a chair leg I'd have walked right past. So I'd say don't ask whether to trust it. Ask what your project actually needs, truth or convenience, and keep those outputs apart.

Started out in the 90s tracing parts with a desktop touch probe, one point at a time, then building surfaces from cross sections in Cadkey. Slow as molasses but you knew every millimeter of that part by the time you were done. That discipline is what I'd worry about losing. The AI gives you a pretty answer and no reason to look closer.

My habit now is to archive the raw scan with the job, unchanged, same as I kept old probe files. Six months later when the client asks why the model differs from the part, you'll want that file.

Question for those running these tools though: how do they handle a part that's clearly out of tolerance to begin with? Bent bracket, warped panel? Does it model the bend or 'fix' it?

I do mostly quick fixture work and one-off brackets for the shop floor, so I'm way down at the casual end of this. My take so far is it depends on why the part exists. If it's just gotta fit the machine again, the AI's guess is usually fine and saves me an afternoon. But I had it quietly widen a mounting slot on a gate arm once, and that slot was narrow for a reason. Fit it, looked great, broke the interlock logic. Now I keep the raw mesh open in a second window and eyeball anything the tool changed before I commit.

What I've started doing on my hobby stuff, mostly scanning car trim pieces and brackets off my project bike, is running a deviation comparison between the raw scan and whatever the AI hands back, then staring at the areas with the biggest gaps before I accept anything. The pedantic part of me wants the tool to show me a list of every assumption it made, ranked by how much material it added or removed, because right now the interesting edits hide wherever the render looks smoothest. My worry is less about getting lazy and more that the failure mode is silent, you only find out when the replacement part doesn't seat right six months later and you've long since deleted the scan.

I come at this from inspection side, doing first-article checks on incoming castings for a job shop. My whole output is the deviation report, so a tool that quietly 'improves' the surface is useless to me, worse than useless acutally. Ran a trial last month where the AI model showed a gasket face flat within tolerance, but the raw data had a low spot of about 0.3mm that would've leaked on the test bench. So I keep the two files completly separate, one for reference geometry, one untouched scan for truth. My question is diferent from most here though, does anyone know if these tools can be locked to reconstruction only, no smoothing pass? That would settle half this arguement for me.