Is this transaction permissible, which requires the distribution of profits and losses, with a ceiling set for the maximum profit the capital owner can obtain, such that they waive any excess profits beyond this ceiling to their partner?

This transaction is considered a mudarabah partnership, whether the capital is entirely from you and the work is from your partner, or the capital is from both of you and the work is solely from him, as stated by Al-Khiraqi and Ibn Qudamah. There is no objection to the condition that if your profit exceeds a certain amount, the excess goes to the partner, as an incentive for him.