is increasing fin worth it?

[Thaddaeus]

Finasteride has dose-response curve that plateaus over the 0.2-5mg range. 1mg is only slightly less effective than 5mg at DHT inhibition. Maybe that small percentage difference in serum DHT would make difference in your case, maybe not.
If you're looking to reduce DHT levels further you should look at inhibition of 5α-reductase (type I) with dutasteride. It will be far more effective than increasing the dosage of finasteride or look into RU58841 as a topical in addition to your finasteride regime.