There is now a new SafeGDScript language that supports most basic GDScript language features. All supported features are intended to match GDScript 1:1, so that .gd scripts can also be used in .sgd scripts. SafeGDScript is dynamic just like GDScript and gets compiled on-the-fly. The SafeGDScript compiler is embedded into a hidden sandbox instance. As always, restrictions have to be enabled in order to deny access to the wider Godot instance.
The new SafeGDScript language can be used as a script on nodes, similar to GDScript. The extension is .sgd
Full Changelog: v0.47...v0.48