When a member transfers in with training you cannot see
Portable credentials, and why a screenshot is not one.
The problem is not trust, it is evidence
Somebody joins with real experience and no way to show it. You either take their word and risk it, or retrain them through material they already know and risk losing them to boredom. Both are bad, and both are caused by the record living inside a server you cannot read.
A credential ID is checkable by a stranger
A CDE Academy certificate carries an ID and a public URL. Anybody can confirm the course, the issuing community and the date, without an account and without the issuing community doing anything. That turns "trust me" into something you can look at.
It shows the certificate, not the person
Verification returns the course, the issuer, the date and whether it is still valid. It does not return anything else about the holder. A credential that leaked a member history would be a worse problem than the one it solved.
What to do with it on arrival
Verify what transfers, then test only what does not. That is usually your local material: penal codes, call types, the departments you run. Put that in a short community-specific course and let the rest stand.
CDE Academy
CDE Academy is the training system inside CDE CAD: courses, exams that grade on submission against a pass mark you set, and certificates anyone can check by ID.