Neill00 I currently have the centre lyric position selected and if I have a time code for each line the current line is in the centre of the screen but if I put the time code at the beginning of each paragraph it snaps to the top.
Hey Neil. I am using a similar setup and it works fine for me. See screenshot

I am using the latest beta (1832) and running on an iPad Pro 18.6.2
I have the Lyrics set to Centred and the auto scroll position also set to Centre. And I have my time code marker on the title of each section in the lyric edito, see screenshot for an example.

So maybe some other settings or config on your device? What are you using?
BTW, I agree, 1/3 screen position would be even better, some time in the future maybe.