How Should You Position Yourself/stand/sit While Training Your Puppy?

I’M GOING TO ASK MY QUESTION FIRST, then give some detail on the situation for those who have time/want to know.
Does sitting cross-legged OR standing make a difference in training a puppy?
Does posture/position make a difference in how a puppy will react?
—-DETAIL!—-
I have had a new puppy for two weeks now. He’s 10 weeks old now and taking to his home-base obedience training very well. However I am having a small issue with my significant other who doesn’t want to listen to my advice when he tries to work with the pup. I don’t even know if my advice is wrong, it just seems he responds better to me when I’m standing vs. my boyfriend who likes to sit.
When I train my puppy, at first I was sitting on the ground on my knees. He did great. My boyfriend prefers to sit cross-legged. He did good, but constantly wanted to crawl/fumble in his lap. I understand that being a man that sitting squarely on your knees can be uncomfortable… so now I have moved to standing while giving my puppy directions. He does really well.
My boyfriend still likes to sit cross-legged, making the puppy want to jump and play in his lap while my boyfriend tries to give him commands. I tell him that maybe if he stands the puppy will not do this, but he refuses and wants to stay sitting, because ‘he (the puppy) should know/listen’ or ‘he’ll eventually get the idea that he shouldn’t jump in my lap’ after time.
(we do let our puppy crawl into our lap when we play with him, so I tell him he shouldn’t verbally punish him for getting in his lap because we allow this during play time. I feel like it might be confusing for the dog.)