Exactly. A cumulative effect of many different drugs (this also includes drugs outside androgen compounds and via different routes of delivery) can cause an increased workload on the body to metabolize it, and then excrete it. This workload can play a factor in many different body systems in general, and can even influence the efficiacy of other systems. The significance or degree of that can vary between the compounds that are involved - to the the individual themselves.
I agree that our applied knowledge, education, and personal experiences can help to validate some things for us on an individual basis. However, ancedotal experiences just aren't going to demonstrate much at all in terms of demonstrating actual safety either way. Blood work is considered by many to be objective information to support a hypothesis (and it can be in a controlled and fully disclosed environment/setting), however, as i said before, there are so many unknown variables that can play a factor into the equation (mainly in this particular setting), that it's in all honesty a moot aspect all together in terms of support.
The liver is most certainly a very resilient organ, and the only organ in the human body capable of actual tissue regeneration (but it can be beaten into submission.) The "broscience" in regard to actual hepatic function and potential toxic stress is seriously laughable at times, but that whole issue can and will be drastically different on an individual basis.
I'm not here to rain on the parade though - just offering another view point. I'd be a hypocrite to say that i haven't stacked compounds in the past; because i most certainly have done that. This doesn't mean that i necessarily support that methodology either, but we're all adults here and can make informed decisions based on the information at hand. Being a man of medicine myself - i tend to err on the side of caution more often than not when there isn't at least some type of meaningful evidence to support safety.
I've finally had the opportunity to start reading your book, seth. Looks like a good read my friend.
I have a quick off topic question though - do you plan to make a more in- depth book in terms of the content in the future?