The major differences between the L85A2 and A3 are that the A3 has a modified upper receiver, a fully floating barrel (so as to improve accuracy), as well as a full length top rail replacing the Weaver rail and allowing the mounting of various different sighting systems.
All of which are for Operational reasons but none of which are required for Cdt shooting (and certainly not at the cost of bringing the L98A2 up to equivalent A3 standard).
Some L98A2s do have have A3 changes to the body but are still A2s. This doesn’t mean you get the fancy rails or anything though.
As far as I know, the L85A3 is still on the cards for the ACF, but we have a syllabus rewrite nearing release and they don’t want to add it until syllabus changes have been rolled out for everything else.
They are often ran by service instructors as an experience piece. I know CCF, ACF and RM units that have done that and it’s well within their remit and often encouraged especially for the older more experienced Cadets to keep them interested and developing.
Insurance is the same as for any other activity. In the same vein, risk assessments are done as they would be for any other activity. Identify risk and try to mitigate it where you can. Unfamiliar subject? Get a qualified instructor. Going into building or through holes in walls? Helmet + gloves. Cadets firing in enclosed spaces? Eye protection.
I ran/organised FIBUA trg for a couple of ATC Sqns when I was at Larkhill - they enjoyed it, and it was a training tool to learn and experience more important things than FIBUA.
Why wouldn’t you want cadets doing something they would enjoy, get a great deal out of, and that’s pretty safe?
Technically it’s not called FIBUA when dealing with Cdts, but TIBUA (Training in Built Up Areas). You need to have SA(M)07 qualified staff to run it (as well as enough Excercise Assistants).
I’ve run it with the ACF at the Lydd training complex.
An upgrade to the L98A2 - I pointed out that the A3 upgrade to the L85 was for Operational purposes ie shooting, and for which there is no requirement for Cdt purposes.