The Rolling Wave marked Ennis' centenary with more programmes the following two weeks, which had a cocnert fro9m the Seamus Ennis centre in The Naul. I didn't link those but they are easily found once you get to the first programme, linked above.
The version of Doireann Ní Bhriain's 'Hand me down' I have runs just short of an hour. I don't know if there's still a full version available online. I downloaded mine from TG4 at the time.
TG4 had quite a few bits connected to the centenary, including the bicycle diaries, those are now no longer online.
I did notice, but didn't watch, they had a programme earlier this week covering Lomax's 1951 field trip that Ennis assisted on. I believe I have seen it before. It's here on the player : Lomax in Éirinn but it looks like it's Ireland only so you may need an identity cloaker or whaever you use for that sort of thing.