The most laughable bit is that these checks only apply to convictions which can be traced against you within the UK and / or subject to the UK Rehabilitation of Offenders Act 1974.
Thus anything that one might have done beyond our shores is of no consequence, e.g.
I could be a paid up member of the IRA / ETA / AlQeda / etc
I could be wanted in, say, Bosnia or Sierra Leone, for gun running / rape / torture / extortion / murder / genocide
I could be the ring leader of a people & drug smuggling organization in Far East
I could be living off immoral earnings from a string of child prostitutes in India
Heck, I could even be a piano player in an Aberdeen whorehouse
....... and Disclosure Scotland would know diddlysquat about any of it !