You can choose to freeze things you like about instrument #1, and breath those into a morph with instrument #2 and #3 and vice versa - like just mics, or a bunch of other things.

I'm mostly OK with not freezing anything to save time also, found rather few negatives in allowing all things into the morphing.

There have been times in morphing where I changed small details about reverbs and timings in each instrument, and the effect remains after flattening.. it's better than I imagined it could be.

Sometimes I'm going for specific things but right now, feels like the sky is the limit with unfrozen morphing between interesting combinations.

If you kept the default parameter freeze value as is, the unmorphed (freezed) parameters, especially the Output settings, may not be the same between piano 1 and piano 2 giving rise to a different result. For example, in one case you use the mics of piano1, in the other case those of piano 2.

Ok .... so it gets a bit more complicated than I had thought.

I thought of it this way ....

Blend the characteristics of piano 1 with the characteristics of piano 2 in the ratio described by the percentages shown in the morph definition.

That will produce the morphed piano.

However, I created a morphed piano with 2 pianos and then created a morphed piano with those same 2 pianos but in the opposite order.

In each case, the ratio was 50% - 50% ... So, I expected no difference in the morphed piano sound.

Those 2 morphed pianos sounded different.

Is that possible ?