“Technique cards” are highly useful, I’ve used them for 4 decades. Much of what is on this type of instruction is fairly benign, sequencing and ‘this goes here’ type of instructions. BUT they do need guidelines based on risk. IF the change has a science/engineering effect on the product it needs to be reviewed by people who actually know why certain things were specified and what the effect will be of the change.
For example if there are 4 screws in a particular pattern, the sequence of tightening can matter. ( you are applying force/tension on the product). Someone might want to change the specified pattern to make it easier or faster - but it could put end up damaging the product. Been there saw that…
Another real world example: a mfg engineer was struggling with wire routing in a chemical analyzer; the wires kept falling in to the instrument so he went out and bought some hot melt glue at a craft store. He didn’t think about the effect that any outgassing of the glue and it’s contaminant (this was craft glue, not electronic grade controlled glue) might have on the electronic components or even the chemistry analysis. His heart was in the right place but his engineering thinking was restricted only to the problem at hand and not on the effects.
So YES. Changes to the technique cards would require review, assessment of the effect of the change and approval…