Well, Sanjis mom seemed mainly against the fact that the modifications would turn her children into superhuman sociopaths that are enslaved to judges will, if they were just super strong and durable but were normal children mentally, maybe she’d have been fine with it? and with Sanji if diable jambe is an effect of his modifications, I think his mom would be ok with it, since he mostly uses it to protect his crewmates, women, and beating up evil ppl.
As far as we’ve seen, Sanji hasn’t gone all out in the new world, the only times I think we’ve been confirmed to see him using armament haki is against judge and when he was around Caesar, so it’s possible he didn’t use it against Doflamingo, Niji, or Vergo, and haki, especially hardening, is such a boost to damage, that stacking that onto diable jambe might have done a lot more damage when he was attacking doffy or Vergo, and Vergo was bleeding anyway after taking his kicks and doffy did mention that his physical power was impressive.
Also, his haki skills are more impressive than they seem, Luffy mentioned in fishman island that his haki is great for defending against blunt strikes and impacts, but not great against bladed/piercing attacks, like Hodys bites, but Sanji took Judges raid suit spear head on with haki, so while his armament offensive skills haven’t been very highlighted, his armament defensive skills seem more versatile than Luffy were during fishman island. Also, Katakuri seems to be able to attack and evade anyone as long as he is focused, and the other person has a lower level of observation, but Sanji dodged his jelly bean attack, and we know observation is his specialty, she could have badass observation powers that we haven’t seen yet, observation haki can be used to sense everything on an entire island, hear voices of everyone in your range, see the future, we don’t know for sure the limit of Sanjis.
The raid suit is the perfect tool for him, it boosts kicking attack power, defense, stealth ability, and flight mobility. It makes sense that the Germa had a suit to match the comic, since the comic character had to come from somewhere, and making it an invisible and giving black as the color seems like a way to say that he’s the black sheep of the family and that they havent seen him. Other than the stealth ability, which is all the suit, as the others have suits that compliment their specific powers, it’s just got the standard abilities, and Usopp and Franky could upgrade the crap out of it, it’s actually super lucky that one of the standard suit powers is that it can’t be damaged by fire and Sanji uses fire as a weapon
Also, when he fought page 1, who is literally one level beneath the All Stars, he was basically just testing the suit and didn’t use haki or diable jambe and seemed to be winning, if he fights serious and uses haki invisible jet enhanced diable jambe raid suit foot kicks, he could grow as the fight goes on enough to beat a yonko commander, Jinbei is techni yonko commander level since he fought ace to a draw, and I can totally see stealth black Sanji going toe to toe with jinbe.
