Would love to see native Safari profile support. Apple exposes no API for it, but there's a workaround I already use: Safari allows to choose a profile for a domain, so route through per-profile subdomains:

1. You need N subdomains serving redirect pages, e.g. work.example.com, personal.example.com. Each page just redirects to #fragment in url, e.g. when opened with work.example.com/#{encodedTargetUrl} JS just redirects to target URL. One wildcard subdomain is even better
2. In Safari settings, manually select a profile for each subdomain (work.example.com -> Work, personal.example.com -> Personal).
3. Finicky rewrites a match to that subdomain -> Safari opens it in the right profile -> page redirects to the real URL.

Finicky config example:

const route = (profile) => (url) =>
 `https://${profile}.example.com/#${encodeURIComponent(url.href)}`;
const ghRepo = (name) => (url) =>
 url.host === "github.com" && url.pathname.split("/")[1] === name;
export default {
 defaultBrowser: "Safari",
 rewrite: [
 { match: ghRepo("workstuff"), url: route("work") }, 
 { match: ghRepo("fun"), url: route("personal") },
 ],
};