Spacing on small staves

I often use small staves for the piano part in a solo piece with piano accompaniment. The small staff visually emphasizes the piano staves, but allows the pianist to read the solo part.

However, in my view, the spacing in the small staff is generally too wide, especially when the solo parts have lots of ornaments, runs etc. Those tend to blow up my piano scores. In the following example:

I feel the need to manually adjust the second measure in the solo part to match the same passage in the piano part:

To my eye, the latter looks better.

So I'd like to open this topic for discussion: are the spacing rules in small staves correct the way they are or do they need to change to fix this? Are there any better workarounds?