Arena - An Encounter Zone Overhaul (1.2.0) --- Infiltration - Quest Expansion (1.01)

USSEP (4.3.1) + USCCCP (7.10) --- zzjay's Horse Overhaul (1.5.2). Technically this does not require either USSEP or USCCCP.

Imperial Mail - Post and Banking Service Continued (with LoTD support) (2.22) --- Skyrim Souls RE - Update (2.4.0)