Use one V3 onion for all tpo domains.
onion.torproject.org
Current listing is a mess. Why not use one V3 onion and "use its subdomain"(like whonix do)?
e.g. www.v3onion.onion, trac.v3onion.onion, update1.v3onion.onion
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information