MIAMI — The next time the Miami Heat play at Kaseya Center things could look a lot different — and for more than the plans for a new scoreboard. Down 3-1 to the Boston Celtics in this best-of-seven opening-round Eastern Conference playoff series after Monday night’s 102-88 home drubbing, the Heat only will play at home again this season with a Wednesday night Game 5 victory at TD Garden. Based on the lopsided scores of the Heat’s losses the past two games — with the deficit on Monday night cresting at 28 — the expiration clock on their season is ticking. Loudly. “Our guys really want to get this thing back to Miami and have just a great game in front of our fans,” coach Erik Spoelstra said.