Every public facing document I have seen makes no mention of modules, there is a openreach page which states a standard SFI fee which is payable when no fault is found or a fault found on end user equipment.
The modules are nothing to do with the EU. The ISP decides which route to take ..... 1) Frames check only ...... or, 2) Minimum 'Base Module' whereby the engineer visits the EU's premises. The ISP can decide whether to pre-authorise other modules for the engineer to follow up on, if they feel it is needed.
Given its the end user who has the issue and its their property you attending I would say it has everything to do with them. you may not see it as a visiting engineer, but remember its these end users that pay your wages, no end users means no income for isps or openreach.
Even your new CEO has admitted there is a problem in how end users are kept out of the loop.
Think about it, end user has to take day of work, to wait for an engineer, and their time is wasted because isp didnt book right module.