SEO when moving HTTP site to Netlify - 301 Redirects

I am moving my old HTTP site to Netlify and need some guidance on 301 redirects and SEO.

I will be using netlify.toml for redirects.

Netlify will automatically redirect http://www.domain.com to https://www.domain.com so I’m assuming that a redirect rule is not needed for this case.

Question 1: For http://domain.com to https://www.domain.com - should I do this in DNS or 301 redirect rule in netlify.toml?

For the following URL

http://www.domain.com/directory/page1.html

Question 2: Should I use relative or absolute URLs to redirect? Which from below would be a best-case scenario?

[[redirects]]
  from = "/directory/page1.html"
  to = "https://www.domain.com/directory/:splat"
  status = 301
  force = true
  
 [[redirects]]
  from = "http://www.domain.com/directory/page1.html"
  to = "https://www.domain.com/directory/:splat"
  status = 301
  force = true

The domain that you set as primary in Netlify, will be the one all the other domains of that website will redirect automatically to, so if you have set www. as primary, you’re good to go.

Relative URLs would work fine if they’re setup correctly.

So while the redirects would work, I’m not sure if SEO would be absolutely fine or not. Like, 301 redirect are honoured by the robots, but you never know.