By not failing? You’re asking if they’re willing to commit sacrilege by kneeling?
If this is actually you that is electing not to kneel, then learn what is proscribed and what is possible, and do that. If you cannot do any of the things that are proscribed, then do the most reverent thing you can manage. If you are willing to commit sacrilege for any reason, then take that to confession. If you are concerned that other people are judging you unjustly, then offer that possibility up as a penance on behalf of their souls and your own. You do not need to defend yourself against their charges. As long as you have not judged them, you will have done them no injury. Be charitable, and you will be forgiven if you have suspected the innocent. If you are correct, you will no doubt win forgiveness for the sinners who have nevertheless presumed to accuse you. This is the example given us by Christ.
If it is not you, then let the priest presiding concern himself with educating those who aren’t following the GIRM. That is his concern, not yours. Again: be charitable to those you think guilty, and you will be forgiven if you have suspected the innocent. Love covers a multitude of sins.
Pray that those who have been “chosen ministers and dispensers of his mysteries may be found faithful in fulfilling the ministry they have received”, but don’t take on their responsibilities by correcting people who have not asked for your guidance. That is not the responsibility given to every Catholic, and there is a reason for that. You ought to stop anyone who is committing an act that is, objectively speaking, always a sacrilege. Other than that, unless the act seems to be something that the person is trying to conceal from those with an office to correct them, you need to mind your own business.
Objectively speaking, it is not always a sacrilege at all, let alone a mortal sin, to fail to kneel at the proscribed moments during Mass, so this is not a matter for the faithful to take up with other lay persons who have not consulted them for an opinion.
I know this can be a source of great anxiety for those blessed with the Holy Spirit’s gift of piety. This anxiety can, however, be the evil one’s way of rendering the gift of piety sterile or even poisonous. Satan has little recourse against saints, save to harden them with pride and the desire to control what is God’s to control. Beware of that attack! Be assured that you will be totally faithful if only you pray that every soul present at Mass is present and reverent towards the Lord, particularly in his awesome, wonderful, and unsurpassable presence in the Most Blessed Sacrament, and that God’s charity truly reigns over all, a thing for which our Lord thirsts above all things. Then that beautiful gift of piety will be the fragrant flower and will bear the fruit that the Holy Spirit intended when he gave it to you.
I hope this helps.