I don't know it it is said already, but please all be aware steroid induced diabetes can give you different lab results, it is not comparable to normal DM 2! If you take your prednisone in the morning, your fasting glucose level can be quite within normal range. For me it was even a bit low (without any DM medications).
It is somewhere between 1 - 4 pm hyou should test your glucose level.
Especially if you eat around 1 pm, test it 3 pm.

About alt day p, I try it when I want to -and can- taper down.
Now for example, I take 16.25 on Tue, Thu, Sat and 15.625 on other 4 days. I really don't give anything about docs thinking this is such a tiny dose difference it doesn't mean anything. I know my body, and after over 6 years over 0.5 mg/kg daily, 6 years of war and disaster caused by P, I rather take it very slowly. Adding an 'alternive' day when I feel it's possible. I do feel worse at the lower dose days the first week especially.
After a few weeks everyday 15.625 I'll probably start 1 day 15 a week and slowly go to 15 mg every day. That would be so awesome if I can reach that.