Hi western,
You are right that the decision will be down to GWR at Reading, whereas at Ealing Broadway it is solely down to TfL. I’m a bit confused about why four trips on the escalators are necessary for one interchange, unless you’re adding together a return journey? Is there a quicker way to get between platform islands without going up to the ticket hall?
I guess the reason that GWR aren’t keen is that it might encourage ticketless travel from smaller country stations to Reading with just the bit between Reading and Paddington paid for.
You might get more luck raising the issue with your MP given that GWR will eventually be subsumed into Great British Railways under full control of the Department for Transport.