I would be cautious

US immigration requires every alien entering US to declare citizenship and the alien will be treated accordingly. That is, you can not be a Canadian or a Chinese in US at the same time.

If you claim Chinese, you need an H1 to enter US. If you claim Canadian, doubtful you will be granted H1 status using your I797 which I suppose to have stated you are Chinese citizen. You still need an H status to work in US as a Canadian although no visa is required.

Same thing happens when you go back to China. If you use Chinese passport to enter, your passport will be stamped. Upon leaving, if you don't have a valid H visa, you may be denied boarding. If you use Canadian passport, you don't have an entry record and Chinese visa. Honestly, I don't know whether you will run into trouble or not like that. But, if someone does decide to go after you, you have no defense. If you use Canadian passport to go back, you need a visa and you Chinese passport will be cancelled. In that case, I don't know whether your H1 is still valid or not. I presume you need a valid Chinese passport.

It is a delima for us. I wish you good luck. But make sure before you go on your trip.