If the buyer adds those conditions, then it seems like it doesn't trigger that clause in the contract anyway.
I am unsure if I parse that sentence into what you meant to say.
I am quite sure that if a buyer adds conditions to an offer which are of any substantive and costly nature to the seller, then the offer is not considered a "full-price offer" and may be refused without penalty by the seller. At least in the States where I have bought or sold a residence.
BTDT.
Your State may have different regulations or laws about what is permitted in residential property sales contracts. And commercial property sales contracts have even different rules and limits. It may be wise to check with a real lawyer for definitive answers in a specific circumstance.
The original scenario which started this rant (seller refuses a full-price offer, agent sues and collects a commission on the prospective sale price) is absolutely possible and does happen rarely. The legal costs take up too much of the proceeds and time of the agent, so it is not usually worth pursuing.