My baby boy is 9 months old and i'm really struggling with finger food...?

we've tried everything i.e. bananas, wotsits, breadsticks, quavers, biscuits, rusks, gingernuts the whole 9 yards but he just doesn't seem to grasp that he needs to chew it. I personally know that he will learn eventually and think that consistency will be the key for example giving him bananas for a week so he masters that then baby wotsits the next week for a new texture etc bt my partner is a really bad worrier and i know she just loves the bones of him but she is petrified he will choke and as soon as he butes a bit off she panics. i try and reassure her that his gag reflex is really sensitive and if he has any trouble he'll cough and gag immediately and then we'll know to get him out his high chair and get the food out of his mouth/throat accordingly but it is really getting her down now and i want to say the right thing to help as i am always in work and cant help out with the feeding as much as i want to nor as much as she needs me to :( please help