It seems that several people have had the same idea. Fuse at 7A at least, sling any leads rated at less than 7A. That's what we do.
Al our leads are marked! A bit anal I know, but how else to know what's out there. Just recently w have seen quite a few dodgy leads - after years of them being OK - mainly fuses missing!
The things I hate most are leads with welded 13A ends - the plug top is welded or glued on to a hard plastic body and ones with hard plastic IEC ends which seem to want to drop out all the time