Filter animations not working in Safari

[wwwonka]

I have a blur applied to my SVG and using KeyshapeJS to animate it. Everything works great, and with amazing performance, even in Firefox which is usually a culprit in that regards. Although nothing happens in Safari. Probably because of the -webkit-filter prefix needed for Safari.

macOS Mojave 10.14.6
Safari 14.1.2

[Pixofield]

I tried adding -webkit-filter to an SVG file, but it didn't seem to fix it. Here's what I tried for static graphics copied from Keyshape:

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 240">
    <rect width="114" height="76" fill="#7b2020" filter="blur(10px)" style="-webkit-filter: blur(10px)" transform="translate(103,82)"/>
</svg>

Do you have an example which uses -webkit-filter successfully for SVG on Safari? According to my knowledge, Safari doesn't support shorthand filter functions for SVG at all.