May I use two 72- or 144-hour free visas in one month

Hello,
Being French, I plan to fly from Paris to Shanghai (stay 5 or 6 days with the 144-hour free transit program), then fly to Phnom Penh. After travelling on land to Bangkok, I then plan to fly from Bangkok to Kunming, stay 2 or 3 days in Kunming, and then fly back to Paris. Do you see any problem with this plan?
Best