These are the new guidelines however they are flawed in my opinion because they are based on the dose of estrogen applied, rather than amount absorbed, and follow a one size fits all approach rather than individualised treatment.
I can understand the principle of this as some women are developing hyperplasia on progesterone - it is less effective for endometrial protection than the older progestins used, and the NHS simply hasn't the resources to offer endometrial monitoring.
So for unmonitored women on a decent dose of estrogen it is reasonable to ask them to take 200mg.
Your options are - try the 200mg. You may not notice any difference. There is also no evidence of any increased health risk with higher progesterone doses however none has been looked for. The main complaint is side effects.
Continue as you are and accept that this may mean less good endometrial protection (although you would have to let your GP think you were taking 200mg).
Continue as you are and pay for a private ultrasound every year or two to check your lining. Personally this is the option I would choose.