Movement system selector

Need	Use	Reason / warning
Standard humanoid capsule movement and mature multiplayer support	ACharacter + UCharacterMovementComponent	Walking/falling/swimming/flying/custom modes, prediction, correction, smoothing
A special mode integrated with normal Character movement	CMC MOVE_Custom + custom sub-mode	Standard physics are suspended while custom physics run; custom state may need saved-move serialization
Short deterministic/programmatic ability movement	Root Motion Source or GAS root-motion Ability Task	Participates in Character root-motion networking when used correctly
Animation-authored committed movement	Montage root motion	Root motion takes priority over normal movement physics; gameplay must synchronize montage execution
Modular mode/layered-move architecture and willingness to carry experimental risk	Mover	Epic labels Mover Experimental in UE 5.8
Vehicle, rolling body, non-capsule creature, or unconventional physics	Purpose-built Pawn/movement system	Character and CMC are designed together around Character movement assumptions

Selection procedure

1. Define collision shape and whether the entity must use ACharacter.
2. List movement modes and which may overlap as temporary layered moves.
3. State single-player/multiplayer, authority, prediction, and rollback requirements.
4. State whether motion is code-driven, animation-driven, or selected per action.
5. Choose the most mature framework that satisfies the requirements.
6. If choosing Mover, record experimental status, engine-version lock, fallback cost, and a packaged multiplayer prototype milestone before committing production content.

Do not migrate from CMC merely because custom movement requires C++. The deciding question is whether CMC's Character/capsule/mode/network model still fits the game.