I had a bilateral mastectomy and lymph node dissection in October 2023, flat closure. When I awoke from surgery I was wrapped very snugly in an ace bandage and a compression bra over that. The surgeon's team recommended wearing an ace wrap or compression bra with extra washcloths rolled up in it for compression until all drains were out and there was no more sign of fluid build up, to ensure that the incisions healed flat. It took six weeks to be drain free with no sign of fluid under the skin--a long haul but I am glad I stuck with it.
I hope you find what works best for you!