ML Sound Lab is a direct competitor to Neural DSP. Their free version, Amped Roots , includes one amplifier (a high-gain modern beast), a cabinet, and a few effects.
They offer a 14-day, fully-featured trial on all their products (Archetype: Nolly, Fortin Nameless, etc.), but once the trial ends, the plugin goes silent. free neural dsp plugin
Let's address the elephant in the room.
You don't need the UI. You don't need the fancy graphics. You just need the sound. Here is the ultimate workflow to get a free neural DSP plugin tone using and ToneHunt . ML Sound Lab is a direct competitor to Neural DSP