Why are you interested in running a MainNet relay?
There is no reward associated to running a relay (at the protocol level - there are only programs for that, see below). In addition, the cost is quite high, in particular in terms of bandwidth and storage.
Currently, all the relays are part of relay programs, as detailed on General FAQ
But there is no such program open to new applicants right now.
Not for a personal reason. In fact, in Threefold Tech we have the playground that provides a simple interface to deploy various projects on TFGrid a decentralized internet infrastructure
And we targeted to provide a way to run different types of algorand nodes.
for now, we manage to create the automation process to run (non-participant & non-rely, participant & non-rely)
and work still in progress on (relay, indexer)
so is there any chance registering new applicants will be available soon?