Generating diagrams from text sources - alternatives to PlantUML?

For the DAPT Data Model<https://www.w3.org/TR/dapt/#data-model> diagram, I’ve used PlantUML to generate it from a text source<https://github.com/w3c/dapt/blob/main/figures/sources/class-diagram.puml>, but I have found that the output needs quite a bit of attention to make it pass the W3C SVG validator, and it can look different depending on which machine I run it on.

Has anyone got a good recipe for this kind of thing? Maybe Mermaid works better? Ideally, an example of it being used in a W3C spec would be helpful.

Nigel