testing the strut itself is good for the strut verification but does nothing to verify ability to drop the nose gear without hydraulic assistance.   Only an air test can do that.  There can be bent components, interference, corrosion and other issues that inhibit a properly charged gas strut and prevent nose extension and main gear overcentre lock.   I also do not like removing parts for inspection just to inspect them unless there's a good reason or a symptom justifying removal and therefore I do not remove the gas strut on a time basis.  The risk of R&Ring perfectly working parts is not trivial in my experience and that is from shop and personal experience.