Bike Mielec

There's a limit to how small they can make the HT while keeping the fat DT. This means that to meet the spec'd ST lengths they have to make the slope degree slightly less

Not really. As shown in the Dolan below it just means more work mitring the tubes. Not that difficult with a good mitring jig.

http://www.roadcyclinguk.com/news/images/Dolan_track_champ_hi.jpg