No mention of death being necessary.
What next, claim that a Pope can resign, a conclave can take place, but the elected can't assume the office or the "he didn't really resign even though he said he did" or the "he didn't resign freely" bandwagon?

You referenced up Section 37, which is under Chapter I, entitled "The
Electors of the Roman Pontiff." So that section is not primarily concerned with the details of the timing of the election but, rather, with those Cardinals who will take an active role in the event. Specifically, it allows a time delay of five days if some Cardinals cannot make it to Rome within 15 days after See is lawfully vacant, which is a reference to the provision of
Pastor Bonus, Article 6, which states that the Apostolic See is not lawfully vacant until "the death of the Pope":
Art. 6 — On the death of the Supreme Pontiff, all moderators and members of the dicasteries cease from their office. The camerlengo of the Roman Church and the major penitentiary are excepted, who expedite ordinary business and refer to the College of Cardinals those things which would have been referred to the Supreme Pontiff.Which is referenced in UDG 14:
14. According to the provisions of Article 6 of the Apostolic Constitution Pastor Bonus, at the death of the Pope all the heads of the Dicasteries of the Roman Curia — the Cardinal Secretary of State and the Cardinal Prefects, the Archbishop Presidents, together with the members of those Dicasteries — cease to exercise their office. An exception is made for the Camerlengo of Holy Roman Church and the Major Penitentiary, who continue to exercise their ordinary functions, submitting to the College of Cardinals matters that would have had to be referred to the Supreme Pontiff.In my previous post, I referenced UDG Section 49, which is in Chapter III, entitled "The
Beginning of the Election." That section appoints the exact time that the election must begin. The exact time specified is, you guessed it, "after the death of the Pope" and after "the funeral rites for the deceased Pope have been celebrated." No optional "resignation" is mentioned at all.
Why would you suggest those scenarios that you posit in your last paragraph? As I have shown, a conclave/election cannot take place until AFTER the death of the Pope, according to the law. There is no other option in
Universi Dominici Gregis.