1. If I recall correctly, you can change default recording padding in TiVo > Networks and Settings. Or have a look at endpadplus.

2. There is EPG data until today+4 days (so as I type this, that is up to the end of Friday 23rd). I think "recent software update" is a mistake, but it did change from today+3 days to today+4 days I think in Jan 2018. There is no need to do anything at the tivo end to take advantage of that (except perhaps connecting to tivo service early in the day, as long as it is after about 3am AEDT).

I am aware of two issues with extending the number of days:
(A) it will increase the size of the slices (for example, it will take longer to connect to tivo service and download the guide, and cause more network traffic).
(B) we have no automated way to update the EPG data after it has been uploaded to OzTiVo. We do have a manual way to update EPG data when upstream EPG is updated between today+4 and today+2. But this requires volunteers to look after doing those updates on per city/region basis. If we uploaded say today+7 instead of today+4, for people who are not in one of the few regions where EPG data is manually updated, there is more chance of the EPG data becoming out of date.

Both of those issues are potentially fixable. For (A) we can reduce the size of slices by breaking up slices (currently all Australian channels go into a single lineup for series 3, we could change this to have say per-state lineups). For (B) we could get more volunteers, or try to work out a way to automate updates.

3. Can you be more specific about the source you are talking about? (Feel free to send me a URL privately.) Is the "better quality" because of issue (B) - that we are getting EPG data 4 days in advance and mostly not updating EPG afterwards?