@Purplelibraryguy I wouldn't say he removed his limiter per say, but it's something more akin to desire. Everything that One showed us about Garou's motivations were all about his very strong desires as a kid. He hated the fact that he and others were picked on, and were always forced to play the villain when they played hero and villain. And so, he adopted the villain ideology to say that it's actually unfair how the villains are always for some reason doomed to losing, or etc. He was projecting his own pain as one who didn't power/status being unfairly treated with injustice by those who are on top. Thus, his strong desires against this injustice was his driving force. In that sense, I'd say he's a monster. We see that all human-turned-into-monsters had some kind of strong desire that made them what they are. Garou's desires were to fight against injustice, of which he needed power ... and in his mind, absolute evil, because in his mind the heroes were the personification of that injustice from those on top with power. Thus, he turned into a monster and gained a very standard looking evil monster type look. And the reason why his "face" broke when he was a monster was because that wasn't his true innate desire, he didn't truly want to be evil. It was all a facade which he hid behind, his true desire like Saitama said was to be a hero. He wanted to be treated fairly. Going back to the hero and villain children's play they did, he wanted to be the hero, and not always be forced to play the villain and be treated with injustice by those on top.
So I'd say it wasn't necessarily a limiter removal, it was monsterification but with more nuances to it than your average monster. And the reason why his was so strong compared to other monsters was BECAUSE his desires were to gain absolute power of evil, and to add on top of it his desires were even stronger than anyone else's we've seen so far. And probably, some are just better others. we saw that when the monster cells that people ate turned them into monsters and upped their strength, and that it helped relatively to the strength they were already at. If you're super weak with not much potential, eating monster cells and turning into a monster turned you into a monster with more strength, but that didn't necessarily mean you were super strong. But if you're someone like Bazou (the martial arts tournament guy), who was already somewhat strong and then turned into a monster, you'd become a much stronger monster. I think Garou is even stronger than Bazou, and I'd say even stronger than Suiryu, and thus by monsterifying he becomes something even more strong than everyone else.