[Pansy-Mae]

All blood goes through the liver, so it will get converted no matter what.

yes, of course it does, but the hepatic portal vein goes directly from the gut to the liver, so it short circuits the need to, say, absorb sublingually or via topical creams.

The stomach method is the least effective but safest method of administering a drug because it gets processed by your digestive system and liver before becoming available to your body.

You are missing the point that the liver converts miroestrol to the more potent deoxy form and therefore to go through the liver straight after absorption has to be more efficient.