Harris song has been shared a few times, including in this thread:
Allez Allez Allez was posted on here back in 2018:
since I was just a boy,
I knew that I would be,
Standing on the terrace,
And cheering on our team,
I know we have been down,
You’ll never knock us out,
Together we’re united,
So hear the oxford shout,
ALLEZ ALLEZ ALLEZ
I also looked for 'Take me home, London Road' - found more references to Peterborough than Oxford. Don't know the story but apparently the Manor version got played on the radio not long ago:
https://x.com/ADawsonBros/status/1781642836309397785 (Do our singing lads even remember the Manor???)
Take me home, London road
To the place I belong
On the terrace, at the Manor
Take me home, London road
A small change but this version, perhaps?

I haven't heard the Dembele song (yet), and there was a Kyle Edwards song at Luton that I couldn't remember afterwards.
I'm fascinated by the culture and evolution of football songs and feel like as soon as they get written down they'll change again. There's no central authority organising committee proposing and approving lyrics, it's an almost unique phenomenon in society but ultimately it is just people yelling. But yes, +1 to the idea of having somewhere online to collate them. Then again I'm sure there are 1000x similar suggestions buried in this forum which haven't borne fruit. One key point is that it's usually an evolution of an older song rather than any "new" songs being sung. There's a balance to be struck between the complexity of a song and the ability to learn/spread the words around the ground. I've previously listed 20+ songs/chants which I've heard over the last few seasons and would gladly contribute to anyone wanting to bring them together in one place.
Personally, I picked up more songs in the pub before last season's Reading game than anywhere else. I'm not a great traveller but definitely our away atmosphere is 10x what we get at the Kassam. But without a doubt it has improved at home this last year, and more power to the Block 19 lads who are making it happen.