Homeguard,
If it was that simple then we would have PPLs getting FI ratings and then setting up a Limited Company.
Legally the limited company is a separate person from the person who sets it up.
To follow your argument would mean that this company could be contracted to provide flight training either directly to individuals or through another organisation such as a flying club and provided that the PPL who owns and set up the company does not receive a pay cheque for flying then all is rosy.
That is not the case.
Remember it is the fact that the flight training is "Aerial Work" which requires the pilot to have a CPL. As soon as the student pays for the services provided on that flight it is aerial work. It does not matter if they pay the instructor, the instructor's company, a flying club who employ the instructor unpaid or a trial lesson voucher company.
If the student does not pay for the instruction or if it is a flight test does not pay for the test, it is not aerial work.
For that to happen in the example organisation provided by Bose, they would have to either charge no students for instruction (unlikely) or not charge the PPL instructor student's for the instruction.
Regards,
DFC