How to configure Parcel/LightningCSS not to remove vendor prefixes?

[Joolyan]

Using Parcel, it seems that's it's not possible to stop Lightning CSS from removing vendor prefixes which have been manually added to the source CSS file.

I'm using "browserslist" in package.json to apply the required vendor prefixes, but have found that Safari 12.1.2 requires vendor prefixing with clip-path and and not clip-path transforms. Using "since 2019, not op_mini all, not dead" I get the required vendor prefixes for everything else, but need to add the vendor prefix for clip-path but not for the transform clip-path due to a bug in Safari 12.1.2.

Unfortunately, adding the required vendor prefix to the source CSS, gets removed by Parcel.

Hopefully there's a simple solution which I've missed?