If by "idividuals" you mean companies - it's very rare to prosecute individuals - although the WAH regs make this possible along with CDM as well. The idea of any law is to hold people to account - so that is actually the purpose of any law.
If HSE were to go after individuals it is more likely to be done under HASAW - the penalties are more severe now it includes imprisonment.
I can understand fully the issues raised in this post with experienced scaffs asking why they have to build to TG20 - they don't - but they do have to comply with the law - the WAH Regs specifically - TG20 is just a benchmark that HSE use to measre you against if it is a basic scaffold. If it is not a basic scaffold it needs some kind of design input. If not then BS12811 - if you can interpret it...
This is the standard that HSE expect all scaffolding firms to work to:
Construction - Scaffolding - Scaffold tower industry health & safety
Too much to stick in the post/thread - sorry
Bear in mind that there are a lot of types of scaffold in that list that require design input. It can be a "generic" design - such as for loading bays but it doen't stop it being needed.
At the end of the day what you guys do is down to you. Experience on its own doesn't make competence - neither does training, there are a lot of other things involved like skill appitude and knowledge.
What makes someone truly competent however - in my view - is knowing when you are not, i.e. you know your limits.
Good luck with the footy - hope your teams win.
All the best
Otto