The problem is that once you accept that adjustment is allowable there is absolutely nothing to say where that adjustment has to stop, or indeed if it has to stop at all.
If adjustability is accepted you give Police Forces/FSS Labs Cart Blanche to do what they wish. If it's true that a manufacturer started this ball rolling just because they thought someone was depriving them of work it, and them are a disgrace. Akin to the farcical 12 FPE limit the manufacturers Lobbied for, which was another ball set rolling we're now saddled with.
I don't know what the tactics of Lee's legal team were but the indication is that they just wanted him to plead guilty, which unfortunately is what he did.
Perhaps that plea can be changed and Lee can be represented by a legal team that understands Firearms Law and also has experience of it.
The 1st October may just be the day that airgunning will be the most difficult hobby to participate in.