Generally, using the wix_router.redirect should be fine for SEO. For your case, you can explicitly set the 302 redirect status code, or leave it blank since that is the default code wix_router.redirect is going to use. 302 tells visitors and crawlers it’s a temporary redirect. Here’s a link for more info - A Guide To 301 vs 302 Redirects For SEO
4 hours generally should not hurt your rankings too badly I’d imagine, either way. Just keep in mind that you can’t create a router for the homepage path (“/”). That may require you to handle your own routing using wixLocation.to for the redirecting, although not ideal.