It's not just about that though. I'm a single mum on benefits and live in social housing, work as a cleaner on occasion, but I'm educated to masters level, speak 3 languages, travel abroad, have many friends who are university lecturers etc etc.
All this means that I'm fearless in advocating for myself in most situations, have no compunction in approaching institutions (schools, housing associations, banks etc) to query their decisions, am able to approach anybody to ask for help and guidance, can source free educational activities for the DC etc etc. So, although my financial class would be poor, culturally I'm MC. (I think this is far better than the other way round, but then I would, wouldn't I).
A lot of modern classification systems for class do take this into account- I think in that BBC questionnaire linked above I'm emerging services sector, lumping me in with all the 20 something baristas in Hoxton it would seem 😆 (I'm 50 and live very rurally).