this isn't a topic related to DAVID. So I move it to the ThirdPartyHardware section.
Which doesn't mean that you'll get no help here... but our knowledge about Artec hard- and software is limited.
Looking at some of your results: It will be very hard work .... and maybe the final quality will not be as expected...
Fixing it with means of DAVID - maybe that works:
Fuse each single scan without closing its holes - save;
Load all the fusion_results again, align and fuse this again, now closing the holes.
Hope, you saved your projectfile in Artec Studio.
I never tried an EVA but ArtecStudio with a Carmine1.09 sensor - but I think its just the same workflow.
There are two modes:
LiveFusion and "Scan". While you get a single mesh (Fusion) along with a "Scan" with LiveFusion a normal "Scan" produces a stack of scans (for each frame a separate one - you can see them right clicking on the file in the scene browser via the pop up menue).
Exporting such a "Scan" combines al the partial scans without connecting, fusing them. Think that happened with your first EngineBlock file: It owns several not connected "mesh-layers".
To fix this, you've to do a Fine and GlobalRegistration on the Scan (in Tools) first and some Fusion (also in Tools) after that.
Now there should be another entry in your righthand scene browser named something like "fusion". Export this one...
There should be better support contacting Artec for you paid some bucks to get this hardware.