Would you also have the plug, wiring, fuses, etc. checked by a professional before plugging in a 3Kw hairdryer? or a 2.5Kw kettle? The granny charger draws 2.2kw, 10amps on a 220v, 16amp, less than 2/3rds of the socket's rated capacity and is designed to be safe in a domestic environment.
I think sometimes the advice given here is over the top, we should all be reasonable in our advice especially to potentially new EV owners where we can confuse them, case in point @Yodarapper
If the granny charger instructions say you have the plug, wiring, fuses, etc. checked by a professional before use then do it. If any electrical appliance says have the plug, wiring, fuses, etc. checked by a professional before use, then do so. The granny charger instructions don't say this, so don't advise it.
I am a landlord, and if someone plugged in something designed for a 16amp socket and something went wrong, it would be my responsibility and I'd fix it straight away.