Should I use subwoofer?

Yes! And even in Hi-Fi, if well integrated and in phase positioned in the room it will bring more bass and less IMD.

Just be careful of the temptation to put it in a corner: It will be more bass but by exciting room mods so these more bass will be flowing (the “vrooom”, not a “dry” sound).

Prefer a bigger subwoofer on the line of the speakers and to not excite too much the room mods.