I would have to strongly disagree with phil, especially in saying "most people who study Dhamma seriously are able to see past Thanissaro Bhikkhu pretty easily". Feeling the subtle breath energy in the eyes is no different than feeling the physical breath energy raising the abdomen, imo... One is just a more gross, and one a more subtle movement of energy.
I'm unsure if the OP's question was about manipulating the breath itself, or manipulating the breath towards the goal of pleasure but I would like to comment on both:
First, I know many teachers teach passive observation of the breath as the sole means... but it seems clear from the Sutta's on Anapanasati that the Buddha taught both passive and active parts of the practice. You can see this clear difference in the descriptions of discerning vs training, re: "he discerns, I am breathing" vs "He trains himself, 'I will breathe". "trains himself, I will breath" is a clear reference to actively manipulating the breath.
Second, towards the goal of feeling pleasure... Ven. Thanissaro teaches Jhana, and accessing Jhana through Anapanasati requires using pleasure as a springboard or access point. Beyond the goal of Jhana, manipulating the breath to bring up relaxation and good feelings in the mind at the beginning of sitting is, imo, an extremely skillful way to assist in the process of letting go and greatly deepens concentration. Sensual pleasure and the pleasure that arises from sense withdrawl in meditation are completely different things... Meditation is supposed
to be enjoyable and pleasurable, the Buddha was very clear about this imo.
"There is the case where a monk — quite withdrawn from sensuality
, withdrawn from unskillful qualities — enters and remains in the first jhana: rapture and pleasure born from withdrawal
, accompanied by directed thought and evaluation. He permeates and pervades, suffuses and fills this very body with the rapture and pleasure born from withdrawal. There is nothing of his entire body unpervaded by rapture and pleasure born from withdrawal.
"It's easy for us to connect with what's wrong with us... and not so easy to feel into, or to allow us, to connect with what's right and what's good in us."