Ustadh you mentioned the two views for the end of ‘ASR, however according to both views, if one prays it after those times (but before Maghrib) with or without an excuse, is it considered أداء such that delaying it to that time for no reason would not be Major Kufr (with those who take this view)?

On both views, if ʿAṣr is prayed after the yellowing of the sun but before it sets, it is counted as performed in its time and not as a missed prayer, because whoever catches a rakʿah of ʿAṣr before sunset has caught it (Muslim). If it was delayed for an excuse, there is no sin, and it is prayed in its time. If it was delayed deliberately without an excuse, the prayer is still valid and counted in its time, but the person is sinful and must repent.