I was wondering what is the best way to reduce a too high acidity in a
fruit wine? The goal of course being to keep as many of the original
qualities of the fruit as possible.

Traditionally dilution is given as the way to adjust acidity in fruit
wines. However, this will also dilute the aromas and tastes of the
fruit.

Grape winemakers in cold climates very often also have high acidities,
but they never dilute, but treat the juice with chemical
deacification. This avoids the dilution of the juice, but is said to
also remove some aroma and taste.

So my question is if anyone has knowledge or opinions about which
treatment is most gentle for a fruit wine?

My question arise because I'm making a gooseberry wine where the
cold-soaked, pectolase treated fruit juice had a whopping TA of 20.
Brix was 12.5 so they didn't taste particularly astringent as a fruit.
I diluted the juice to a TA of 12 and reduced it further to 9 by using
potash.
I was wondering what this kind of treatment does for the quality of
the wine.

My goal is to make a crisp, dry sauvignon blanc-style white wine, so
possibly I will have to reduce acidity even further.

Regards
Martin