What things are added when you switch from Delta to skip ahead?

Depends in which insider group you are. Alpha skip ahead first, then, alfa, then delta and omega. For regular users in the same time.

That feature is only available to Alpha,Alpha skip aheads & Beta Insiders at the moment.

As you are in the Delta ring you will still need gold to play any games online.

You must be invited to become an Alpha Insider or Alpha Skip Ahead Insider, to do so You must Very active in Xbox, doing missions and report the bugs You see in the system, as much as You do this, so You Will be Very close to become an Alpha Insider. You
must be at least in Delta preview to become an Alpha Insider, but You Just need to be an Insider to be invited to become an Alpha Skip Ahead, but this one is very rare to be invited and there is a certain number of people to be invited, no more than that,
If You were not invited to be Alpha Skip Ahead certain time, so You must wait a Second chance when they Will invite New members.

Hi, I tried to private message you but it didn't work.

You have to be in the insider preview to download the avatar beta app. It works on the original Xbox One, the Xbox One S and Xbox One X. It is not rolled out by console model but by which Insider Preview ring you are in. It has now been rolled out to all
rings.

Insider Preview has Alpha Skip Ahead, Alpha, Beta, Delta and Omega rings. Alpha Skip Ahead and Alpha are invite only from the development team. You can use any Xbox One family of console in any of the rings.

Not all Insiders have access to not requiring gold for f2p games at the moment.Only Alpha/Alpha skip ahead & Beta rings are testing it.If you are not in any of those rings then you will still need a gold sub at the moment.

I have access im in the delta lvl and it talks about us testing it but it will not work on my Xbox and I’m on the current update for delta and I see the I have a Xbox network id