You need to first select the scene you want to modify (so the settings are close), change the volume of the Part(s) you want to alter, then press [SHIFT] + Scene Button (whichever one is the scene you want to modify, whichever you pressed at first to recall the settings)

The requirement to press SHIFT before SCENE button in order to store into the scene is another area that causes problems.

1. the current scene is 2 - because that is the last one you modified
2. you go back to the home screen
3. you make a volume (or other acceptable scene change) and want to store it into scene 1
4. you press SHIFT 1 - you stored the new volume into scene 1
5. BUT you also overwrote the other scene 1 settings with those of scene 2.

That 'first select the scene you want to modify' is critical to avoid the above problem. Because when you press SHIFT 1 it will store ALL possible current parameter values to scene 1 even if you only changed volume.

So if the current scene is 2 and you use SHIFT 1 to store changes into scene 1 it will be storing scene 2 settings.

IMO the order should be: press SCENE NUMBER first and then SHIFT. That eliminates any possibility of making a mistake on the scene number.

Your finger could slip and hit the wrong scene number and screw things up.

Or, as I have accidentally done on the MODX, you can press what you think is scene 1 but is actually scene 5 because there are only 4 scene buttons and an extra one to switch between 1-4 and 5-8.

I still think the setup of scenes should be made a separate function so that you can set them all up independently from each other and from the performance defaults.

settings current,

... and, timely to your questions: there's a tech talk focused on the topic of scenes coming Jan 31st.

https://www.yamahasynth.com/resources/events/tech-talk-modx-scenes