Just going through it all with twins….. Daughter on a provisional only policy with me as named driver and her as registered keeper on her late grandmother’s Fiesta, £450 with Adrian Flux.
Son had a similar policy on his cheap old Jimny, then passed and has to finish off a partial payment, but now has his Jimny insured with me as named driver on a Tesco black box policy (limited mileage of 8000 per year, but can earn extra insured miles or buy them if he needs to ) for £1999 comprehensive.
As a rule of thumb, don’t renew with the same insurer once they pass. The provisional-only policies can be had surprisingly cheap, but their young driver policies are punitive. You have to cancel a provisional-only as soon as they pass, but you don’t have to stay with the same insurers.
Marmalade are worth a google if you want to put a provisional driver on your own car.
DO NOT front them as named drivers on their own car.