Just for the record, I feel compelled to state that Wikimedia Technical Conference/2018/FAQ#Will there be video recording? (spoiler: NO!) is pretty bogus.
If you merely follow the first link provided to Chatham House Rules, you'll find: "Meetings, events and discussions held at Chatham House are normally conducted 'on the record' with the Rule occasionally invoked at the speaker's request. In cases where the Rule is not considered sufficiently strict, an event may be held 'off the record'."
That is, I have no objection to portions of the event being under Chatham House Rules, but even the original Chatham House Rules caution against over-application. For the majority of our technical questions, there is no need to cloak proponents and opponents, and doing so only makes our decision making more opaque and cabal-like. For those not invited to the conference, it makes it unnecessarily difficult to follow up with proponents of a particular position, contribute additional technical information, or correct a misunderstanding.
And the other arguments proposed seem to be tearing down a strawman. Yes, you can spend a seemingly unlimited amount of money on video production. But in this day and age, a basic and serviceable recording can be made by any one of the participants with their cell phone, sitting in a corner. It can even be streamed live in this manner!
Textual notes are often maddeningly incomplete and lack context. A cheap video-recording promotes transparency and helps fill in gaps in the notes, even if the recording is only viewed a handful of times by a small number of engineers actually implementing suggestions made in that session. The recording can easily be paused, eliminated, or made private to the participants for specific sessions where the invocation of Chatham House Rules is appropriate.
Anyway, I know this is far too late to affect the conduct of this particular conference, but I needed to clear my conscience by putting my strong objection on the record. Restricting attendance, cloaking participants, and removing all but an approved textual summary is contrary to the principles of open and transparent process.