Hakata to Tokyo via Sakura and Hikari

During my next trip to Japan, I'll be returning to Tokyo from Hakata. Since I'm using the JR Rail Pass and don't feel like upgrading to the Nozomi for this leg of my trip, I'll be taking the Sakura and then transferring to the Hikari at Shin-Osaka.

The route I looked up has my Sakura train arrivng at 10:59 and my Hikari train leaving at 11:18.
My question is, will that be enough time for me to get off the train, go through the exit gate with my Sakura ticket, then go back through the shinkansen gate with my Hikari ticket and get to the train on time?

Would I be better off catching the next train at 11:48 instead?

There is no need to go in and out! It is a simple transfer of trains. Should take no more than 3-4 minutes.

If you make the change at Okayama instead. It should be the same platform.

11:18 Hikari should be from Shin-Osaka to Tokyo. There should be 3 platforms to Tokyo bound so you may need to use stairs but there are elevator/escalator so don't worry.

That is a huge amount of time - you might transfer at Okayama, Shin-Kobe (both super fast), or Shin-Osaka. Only hassle is the Sakura trains sell-out.