The in-person meeting wasn't recorded, but I do have some emails and my MP did suggest I write to John Hayes with a 1-page summary.
All the emails together may be a bit much to read, but as a general sense I figured that it would be a mistake to say "surveil absolutely nothing absolutely ever" as that would seem like petulance to a non-technical MP and thus get ignored; also, as I think criminal gangs are just as capable of digital attacks and surveillance as governments, I'm not so much worried about the surveillance itself as I am about the social damage from how this enables blackmail (which requires social rather than technical solutions) and the security damage from deliberately created weak points (which leads to "use a different method for the surveillance you're going to insist on doing anyway no matter what I say and will continue to do even if we remove all the laws supporting you").
In retrospect, and as I'm not a lawyer, I suspect I also thoroughly misunderstood some of the parts of the bill I was reading and objecting to.