'learner insurance' came around because as the mainstream insurance market became increasingly targetted to demographics some insurers started to refuse or impose ridiculous additional premiums to add a learner .
In the old days before no win no fee, crash for cash, whipcash, and "Accident management , like for like ,innit " , you just added a learner for a fairly nominal extra premium and got hit for significant but ( still smaller than today's premiums) if and when you passed and still wanted to be on the family car ...
OP should insure the car themselves as main driver with likely supervising drivers as named drivers, unless the vehicle will geneuinely be used more than 50 % of the time by a parent DO NOT put them as main driver , this is 'fronting' and it is pure and simple fraud.