I am in this issue for 20 years now, long before 3D printer went public, so to say.
Converting files from a CAD format to another CAD format was always a headache, and at lest in the begining it required a lot of post conversion manual cleaning.
Today we have some aid with the CAD proprietary softwares themselves, and less with the Open Source CAD softwares, they catch up slowly thou.
They have all incorporated up to certain levels ways to import or export, and do conversion of various types of files, some better than others, some requiering more or less maual cleaning in the post conversion, very few not requiering manual cleaning at all.
But there are out there some companies offering dedicated conversion software for a large number of saving extensions, that require none or little post convesion cleaning by the operator.
And some shy Open Source attempts too, but really shy.
Please say your in the comments on their quality, attendability and reliablity, also on their pricing per licence/conversion/subscription.
Looking to understand the world of CAD converters better, and I think you are looking into that too.