Official guidelines for HRT prescribing now recommend 200mg micronised progesterone daily with a patch of 100mcg.
This is the same whether it is used orally or vaginally.
There is evidence that vaginal progesterone has a more potent effect, however it is not possible to know who would be absolutely fine, and who would develop hyperplasia, so the NHS has to err on the side of caution and have everyone on the higher dose.
Some individuals will be overtreated on this dose, but as the consequences of under treatment are serious ie endometrial cancer, this is the best they can do.
If you wanted to remain on your current dose, either oral or vaginal, and have no bleeding, the sensible thing to do would be to get a pelvic scan every year or so to monitor your endometrium.
It is not reasonable to expect the NHS to fund this, you would simply be told to take the higher dose, however paying for a scan privately is about £100-200 and some people feel this is worth it to facilitate more individualised treatment.