Is it permissible for the Imam to deliver a sermon or continue the topic of the sermon after the Friday prayer, with mention of the evidence?

If the Imam completes a topic he addressed in his sermon after the end of the prayer, in order to instruct the worshippers in matters of their religion, then there is no objection to that; rather, it is desirable, because it falls under the general scope of the شرعية texts that encourage the propagation of Allah's religion, such as the Prophet's (peace be upon him) saying: "Convey from me, even if it is a single verse," and his saying on the Day of Arafat: "Let the present convey to the absent."