First, I suggest that you check whether the Consular Agreement between the U.S. and China allows you full American Consular assistance and protection if you enter China on an American passport. If you enter China with the Homeland Return Permit, you forfeit such Consular assistance and protection otherwise available to you whilst in China from the American Consulate in China.

You need to consider whether this is important to you.

For Canadian citizens, the Consular Agreement between Canada and China specifically stated that Canadians regardless of national original, will be entitled to full Canadian Consular assistance and protection if they enter China using their Canadian passports.

The choice is yours.