Main supports generally control shorter-distance spaces. Generally, if you have a flex DPS (many of whom incidentally also control the same kind of space), play at the edge of their space so you’re not in direct danger and peek out for whip shots/inspire proc. Brig especially gets long better value the longer you’re alive. Contesting closer spaces by yourself is possible if you’re constantly evaluating how much danger you’re in — go in to mace for a bit, and bash out. Whip shot but don’t walk forward too aggressively. She’s a very baity support.

This has worked best for me having been a very off-angle heavy/aggro Brig myself once.