Retired Pharmacist here.
Finasteride and Spironolactone should be swallowed. There is no need for sublingual for these two medications, especially for the Finasteride. Finasteride causes birth defects in a fetus whose mother was exposed to Finasteride. For this reason all Finasteride in the US is coated to prevent dust from the tablet getting to where is may cause a problem. The coating makes Finasteride impossible to use sublingual effectively.
Spironolactone is such a large tablet, I would think that taking it sublingual would be difficult to do. Spironolactone works just fine with swallowing the tablet. Sublingual adds nothing.
The only reason to take your Estradiol sublingual is to avoid the first pass through the liver. Yes, with sublingual you get much higher blood levels initially, but they soon drop to a more normal level. Injections and patches also avoid the first pass effect, but they do not provide the high blood level spike. They were designed for provide steady state blood levels.
As others have posted, blood levels are not that important for transition purposes. You just need to be in the normal female range and with long term exposure, you will reach your goal as well as any other female in your family.
