Ok, so currently the only two options for running a full node are Unpruned and Pruned.

Unpruned costs 350GB. Pruned requires trusting third parties for historical data.

I am proposing a "partially pruned" full node.

Basically, a Pruned full node plus all currently non-zero UTXO.

This can save disk space, plus not having to trust third parties for historical data.

The list of all non-zero UTXO can be constructed from an Unpruned full node. Or it can be downloaded from somewhere.