SHBG isn't an enemy at all, and there's no advantage in driving it abnormally low.
Unfortunately many authors keep saying that SHBG ties up testosterone or other anabolic steroids and therefore decreasing SHBG will increase them.
But this is not true.
If you drove your SHBG to zero right this instant, it would free up only micrograms of testosterone, as that's all that's bound to SHBG! Say you're at 1200 ng/dl and you have 5 liters, so 50 dL, of blood. That makes 60 micrograms, 0.06 milligrams, that will be freed up. That's all.
And that would be a one-time deal.
Just 0.0005 mL of testosterone ester injection, one time, will provide that. How much will that do?
Free testosterone is the determinant of testosterone activity, and the amount bound to SHBG does not reduce free testosterone.
SHBG is a useful transport protein for testosterone, not a "sucker-up" or consumer of testosterone. Testosterone goes onto it, to help transport it, and comes off, rather than being destroyed or consumed by SHBG. Net effect over time, zero. Immediate effect if hypothetically freeing all of it: negligible.
No one gets added gains from driving down SHBG. Bad theory, with no practical results to support it. But it's a theory that doesn't die, I guess because it keeps getting put out there and it seems intuitively sound.