The rules for acquiring and storing are different to the rules for transporting and indeed are two separate licences which are now combined. Makes the whole question very difficult to answer doesn’t it?
I’ve just read my explosive licence. The only mention of quantity is the amount that may may be kept at the address on my licence. This would indicate that I could acquire and transport as much as i want to but not store it!
If lots of people chipped in and collected on the day the no problem. (probably)