Help with changes to improve AWA upwind

I have a Schionning 1480 waterline catamaran, it tacks quite well upwind but I'd like to improve a couple of degrees.

What changes would bring the most/best/easiest results ?

 

Assuming here you mean better tacking angles, ie pointing by saying better tacking, not the inability of the boat to change tacks without losing boat speed and control.

1) Going down the river or along with other currents like tides.
2) Using an engine to provide propulsion in light air, possibly in combination with dropping or rolling in a headsail.
Nothing else easy will become even close to those ones.

If you are willing to do something less easy and or more costly to get less result, then there are of course alternatives that also apply to racing.
But a sensible solutions would require far more knowledge from your boat, sails being used (areas and height and clearance from any solid surface below including water surface if there is nothing solid between), sheeting angles, rotating or non rotating mast with its dimensions, etc. And the performance you now achieve (tacking angles, AWA, TWA, boatspeed, even leeway if known). You might include tacking angles twice, both as shown by GPS based map (= change of course) and change of heading, allowing to calculate leeway. And if sailing in any current that would need to be known too, both magnitude and direction, to calculate other data relative to water instead relative to ground, unless its all already relative to water. And then dimensions and shape of boards and rudders also have an effect, if you expect something else than just possibly better trimming of sails for your requirements, instead of better VMG as is usually the case. Notice that better pointing does not equal better VMG in most cases.
Even with all that available it's still a bit of guesswork or black art, not exact science. Perhaps better answered by someone already knowing the type of boat and its details by practical experience.