Singapore - Baiyun Airport Guangzhou - Macao or Hong Kong by land border crossing

Would the 144 hour Visa free transit apply to me if I depart Singapore to Baiyun Airport in Guangzhou and then tour around Guangzhou for under 144hours, visiting areas including Toishan and Zhongshan, before exiting into Macao or Hong Kong via a land border crossing either by train, car or ferry?

If this is ok, do I simply approach customs upon arrival at Baiyun Airport to complete an application for the 144hour visa free transit? Thank you.