Image management does not support SVG mesh gradients?

If you just want a gradient, see this (while this is for a button the idea is still the same),

Example view with gradient background:

{
  "custom": {},
  "params": {},
  "props": {},
  "root": {
    "meta": {
      "name": "root"
    },
    "props": {
      "style": {
        "background-image": "linear-gradient(red, yellow)"
      }
    },
    "type": "ia.container.coord"
  }
}