Congrats on your first crack Hefe
Here's a few thoughts that might be of help...
I have enough grain to do 5 batches to allow calibration of my equipment...
That is great to see you are committed
If the grain is already crushed, try and use it sooner rather than later and store it as dry and cool as you can.
Avoid a 60 minute mash. The extra 30 minutes does make a difference. Besides saving 30 minutes, there is zero advantage to a 60 minute mash, only penalties.
You'll get some odd readings on these 5 brews but if they worry you, post them up and we'll see if something major is going wrong.
However, the most important thing when looking at numbers (or flavour characteristics) in all-grain is to make sure you have a thermometer that reads well at mash temps. My best advice here is to never rely on a single thermometer - the more the merrier