Confused about the point of ESM presets

[nlwillia]

I'm confused about the resolution of #3828. The current docs warn against mixing preset with transform, but then in an example they do exactly that.

What's the point of having a preset if it shouldn't be used, and why not fold all the arcana into a preset to begin with?

[bjmc]

I'm a bit confused too. We need some custom transform rules to handle .svg files, but I'm not sure where to put them or if it means we'd have to give up using a preset.