Omlet should have trialed stuff like that before issuing it
That made me laugh. Reminds me of a post on here that said the beehaus had been extensively tested for over two years by many exprienced beeks! As far as I could ascertain, they were a tiny bunch of two (relative novices?), along with the consultant (Robin), for one season.
With regards to liquid smoke: this is available from 'well known' suppliers and has been for some time. So, well tried and tested by someone else. Whether good, bad, ugly, or indifferent, results might be another matter. The manufacturer will say it is better than a smoker, wouldn't they!
Regards, RAB