If it needs to heal, it shouldn’t heal in an ‘enlarged state’; if you apply tension on damaged connective tissue, what you are doing is just delaying the recover - I’m basing this opinion on published studies on the subject and also on the opinion of people who professionally deal with connective tissue.
Now this lead to the question: does our penis needs ‘to heal’ after a PE session? I think when you are a newbie the penis is not accustomed at all to the stress imposed by PE, so there is a chance that you have caused some degree of significant damage.Then, better that you let it recover.
For the intermediate or vet PEer, I don’t think causing significant damage is easy; so it makes sense to go on applying some stress after the PE session, wearing a cockring or an extender, because as long you don’t damages tissue, the more prolonged the traction the more pronounced the lengthening effect.