Working with the TEMPO Trainer you can easily get used to those faster Stroke Rates.
1 Year ago my Stroke Rate was SR=1.8. At that time SR=1.5 seemed way too rush, just could not keep up with the Beeps.
My natural rate today is SR=1.5. I can still keep up at SR=1.3 but SR=1.0-1.1 feels impossible.
My advice is to use the Tempo Trainer and gradually increase the Stroke Rate.
Mon: 4 LAPS @ SR=1.60, Then 4 LAPS at SR=1.55, then 4 LAPS at SR=1.50
Tue: 4 LAPS @ SR=1.55, Then 4 LAPS at SR=1.45, then 4 LAPS at SR=1.40
Wed:4 LAPS @ SR=1.50, Then 4 LAPS at SR=1.40, then 4 LAPS at SR=1.35
I am sure within 2-3 weeks you can swim comfortably at SR=1.4.
Let us know how it goes. ALEX