Wethe,
You can use a ball-head hex tool and the narrow size of the hex means the shaft will flex. You can come at the adjusting grub screw at an angle. For example, SLR rifleworks sells 2mm ball-headed drivers for their AGB.
At the end of every shooting session or even in the middle you can take the suppressor off to do your adjusting. You don't want to leave a suppressor on the end of a barrel after a shooting session anyway as they attract moisture and the salts will corrode the barrel. Suppressed guns get filthy so get ready to appreciate the downside of having one. If you use an AGB you can close off the block to prevent solvents and oil getting into the gas system while cleaning. You can't do that with a normal non-adjustable block, or an adjustable carrier. It's not a deal-breaker but a nice collateral benefit. And with an AGB it pays to close and open your block at the end of every shooting session to prevent carbon from seizing the moving parts. I have no experience with adjustable carriers so cannot suggest one over the other.
I would be cautious about comparing the gas characteristics of 300BO and Grendel. 300BO is woefully undergassed due to the high volume 30cal pipe which drops the pressure as the bullet travels down the pipe rapidly. There's no point in using an adjustable gas on a Blackout because it needs all the gas it can get - it would end up permanently fully open.
You can use a ball-head hex tool and the narrow size of the hex means the shaft will flex. You can come at the adjusting grub screw at an angle. For example, SLR rifleworks sells 2mm ball-headed drivers for their AGB.
At the end of every shooting session or even in the middle you can take the suppressor off to do your adjusting. You don't want to leave a suppressor on the end of a barrel after a shooting session anyway as they attract moisture and the salts will corrode the barrel. Suppressed guns get filthy so get ready to appreciate the downside of having one. If you use an AGB you can close off the block to prevent solvents and oil getting into the gas system while cleaning. You can't do that with a normal non-adjustable block, or an adjustable carrier. It's not a deal-breaker but a nice collateral benefit. And with an AGB it pays to close and open your block at the end of every shooting session to prevent carbon from seizing the moving parts. I have no experience with adjustable carriers so cannot suggest one over the other.
I would be cautious about comparing the gas characteristics of 300BO and Grendel. 300BO is woefully undergassed due to the high volume 30cal pipe which drops the pressure as the bullet travels down the pipe rapidly. There's no point in using an adjustable gas on a Blackout because it needs all the gas it can get - it would end up permanently fully open.