I have found that sexual health/performance wasn't as optimal on higher total tesosterone doses, so I'm reluctant to go too much higher simply for the sake of chasing numbers.
The dose doesn't matter, it's how much you absorb that matters, and the resulting serum levels of testosterone.
I subjectively feel better after doing IM injections vs subQ
Very common sentiment.
I think my biggest question right now is if I should follow my provider's guidance of (1) increasing 20mg to 25mg daily, OR if I should consider a more infrequent dosing protocol to increase aromatization?
I don't think either of these options will be effective. Assuming your levels increase proportionately to your dosage, which they do in most cases, and nothing else changes, your 5 mg daily increase will move your free T up to 15 ng/dL and your E2 up to 12.5 pg/mL. Still not great. And injection frequency does not usually affect the aromatization rate in practice, it just moves the peaks and troughs around. If you maintain the dosage and injection methods, and space out your injections, you may end up with an E2 that is even lower than 10 pg/mL at trough, and a hypogonadal free T.
I have really enjoyed the daily protocol for the most part vs previous more infrequent schedules (less of a roller coaster). I know that Nelson is a champion of biweekly injections w/HCG, but there are others like you guys and Vince who are pro daily.
Higher frequency is generally better for everything, except occasionally libido, which in a minority of men can be better with lower frequency. In these cases where lower frequency is preferred, I would theorize their levels, especially E2, are not being maintained in an optimal range for them on the high frequency protocol. The large swings on the lower frequency protocols allow you to spend some time at levels that are optimal for you, despite the overall dosage / levels being wrong.
I'm also curious why my total & free T levels keep going down on higher doses over time, as well as if the daily injection schedule is increasing my SHBG (it used to be in the low 30's).
The daily injection isn't what is increasing your SHBG. Your SHBG is rising because your absorbed dose of testosterone, and your free T, are dropping. Testosterone is what depresses SHBG here, and the lack of it allows SHBG to rise. Be careful not to mix up the causal relationship.
In my opinion, there is nothing wrong with your protocol that needs to be adjusted here in terms of dosage. If anything, your current dosage SHOULD be too high for someone that wants to avoid supraphysiologic levels. It is the execution of the protocol that is wrong. 5/16" needles are wrong [for you]. There are men in the world pinning subq with 5/16" needles with great levels, but you are not one of them. We have objective evidence that what you are doing is not working correctly, and in fact, is working less and less correctly over time.
For context, my levels on 20 mg of test cyp daily with no hCG were: Total T 1502 ng/dL, Free T 35.5 ng/dL, E2 37.5 pg/mL. These are with 1/2" needles in the ventroglute, buried to the hilt and then pushed a bit further so as to depress the subq fat. If you want to mix it up with delts and quads, great. 1/2" needle, bury it in the muscle, repeat labs, and behold your transformation into a normal responder to testosterone.