Did Skoda apply any stone chip protection to the lower area of the sills as standard?

Do you mean PPF, or actual underseal?

Underseal, beneath the paint.

On my mk2 octavia and sons mk1 fabia the lower outer sill and inner has an orange peel effect which is thick plastic stone chip protection then overpainted with gloss colour. They both have(had) clear plastic on rear wheel arch/sill area

Alasdair

Thanks for that, that is what my 2018 Fabia estate has on the sills. I assume therefore it is a factory finish.

This is one of the sills on my Fabia.

its fairly thick as I had to remove some to patch sills on my old octavia. Its good protection but on mine over time moisture got behind it and ended up with holes.

Weird thing is my sons mk1 is a few years older 55 plate and its still perfect but my 58 plate octavia is now a parts donor car as sills have gone past repair.

Alasdair