To speed up the sublimation process, you may want to get more heat presses. Most production facilities will line up multiple presses for increased output.
The next best thing to do is use automatic presses. This results in far less clamping/unclamping press-handling time and reduces operator fatigue. From there, twin-station automatic presses allow one operator to load and unload the bottom table platen while the other side is pressing.
To keep heat presses working their best, Teflon and/or paper coversheet usage keeps the press clean and avoids buildup problems on the platen and contamination of the padding over the long term.