For goodness sake, don't let the UK education politicos hear about this, they'll immediately make it compulsory in all schools - except private ones, of course, and possibly academies, until the evil "public" (i.e. the ones open to everyone else ... also classified as "state") schools have had it tested on their long-suffering teachers and pupils .
This sounds like just the sort of thing that would appeal to anyone without any experience of teaching, no experience of non-fee paying establishments, and looking for an opportunity to cut budgets even more ......
Good grief .........
Frankly though, this sounds like another terrible amateur mish-mash of theory, hearsay and anecdote paraded as the answer to the perfect education, and not one I'd want to inflict on any child.
The parents concerned may feel they've done something marvellous, and perhaps they have, in their particular circumstances - but to offer it as a blueprint for other parents ?
That's without going into the merits, or otherwise, of whether home-education is a sound idea for more than a handful of cases anyway.
As mentioned, this regime depends primarily on the parents ability and education - and that they aren't tempted by the possibilities of indocrtination.