As a scenario player, and a game organiser - I've often said this and expect I will be saying it again ....
There are measures that have been taken over the years that I have often felt scenario was following the tournament scene, (e.g. UKPSF air training and air passes), either I've been wrong and have seen people discussing measures and they've not been taken up in general or they have been taken up and later faxed out and forgotten
With UKPSF air passes and the training given at events, this only gives general air awareness and the individuals sign a form stating they understand what they have been shown, and that they are aware that they are responsible for their equipment
It's not a disclaimer for the site, and it does not take on responsibility for allowing you to use and fill your system
Checking a cylinder at a site is just one control measure, the two main factors are checking it is uk legal and in date
But part of even just a general check is condition. If an alumimium cylinder has had the paint worn then that's fine, it does not affect the integrity.
A full look over a fibre cylinder will find scratches etc, but also takes longer.
If a cylinder looks like its been around I'd give a bit more of a look over for its condition
I'm not running weekly games so haven't checked over thousands of cylinders, but I've only picked out a handful of cylinders to reject
These have been a brand new us dot cylinder (the first time that I met a guy that I now know well, as he said to me recently be was a kid on his first time paintballing and didn't know until I told him), a couple that were recently expired and at our game the other week a group of lads all had new cylinders, the majority had new steelies a couple of months in but one had a fibre cylinder.
He was disappointed to find me rejecting it as out of date and was worried he had been conned.
In fact it had about 2 years life left but had no test markings at all. This implies its been used for 13 years and missed 2 tests, perhaps it's been stored and not used whilst out of date. He had paid £80 for it so was unimpressed at the prospects of not being allowed to use it without paying more for a test
(I don't know where he bought it, but he confirmed it wasn't from the forums, which all have rules that would prevent sale of an out of date cylinder)
I did let him know that £80 was the general going rate for second hand fibre cylinders - even though depreciation values don't always add up.
Back on topic -
I would not be impressed if chrono checks and bottle checks were not taking place
It is the responsibility of the individual, but as above the individual may not be fully aware