I am somewhat sympathetic to your position, but I don't think the question can be answered simply. Or rather the simple answer seems to be zero, zero and zero. BUT
Back in 2014, the ORR was considering whether fitting of CDL to slam door stock used for charters on the main line was really necessary. Then came the fatalities at Balham (442) and Twerton ( HST). Those events caused a rethink leading to their 2019 decision that the exemption regime would end in 2023. The relevance of those two sad events to stewarded charter operations is of course arguable.
Also, where you have rare events such as these, it is also relevant to consider 'near misses' in which category there are at least three in the public domain, one at Bath spa station, one at York station and one at Reading. Those could have resulted in injury but didn't.
Then you come to the question of what the appropriate mitigation is--- are window bars, stewards and internal door locks enough, what does CDL add? Does the risk change justify the cost? Whatever you or I may think, the regulator decided it did and when legitimately challenged at the JR, its position was comprehensively upheld.
So where we are now is that WCR are seeking a further temporary exemption on the basis of ORR's need to consider WCR's application which seeks to demonstrate that, in the circumstances of the Jacobite, CDL adds nothing to the overall safety case. But that looks like an attempt to rerun the JR.
There is a good fifteen minute review of this on the Green Signals podcast #26, the double act by Nigel Harris and Richard Bowker.