ac evaporator

No, it happens "at both ends." As I tried to indicate, the entire system must be "matched" up to a point.

Compressor capacity is probably least important so long as it's not too large in relation to evap and especially condenser.

In the "refer" and other commercial world, there is actually systems that are variable capacity, and in older large refer installations in grocery stores, sometimes one system will have more than two evaps in different coolers with independent controls.

"These are not ideal" for performance and efficiency.

Just use your head and "think" about what is going on. An A/C is a "heat pump" that is, it is absorbing heat at one end and rejecting heat at the other. Also, the compressor and mechanics of operation ADDS more heat that also must be removed.

In the case of most residential systems, where the compressor motor is inside the compressor shell, that motor heat and friction is also added, and must be rejected---removed.

If you cannot easily change the size of the major components, the things that you somewhat CAN do is

change the airflow (blower) through the evap. Less airflow means less heat absorbed, and less system capacity is needed

change the airflow through the condenser if possible. Less air means higher head pressure, and less system capacity "to a point."

change the charge (refrigerant) This is mostly to protect the compressor after decent operating temps / pressures are reached

change the TXV or orifice up or down. This is probably the single most useful tweek you have.

If you are inventive enough, you could even change the speed (crank pulley) of the compressor.