Auto-fill "rate" property to temp basal if missing

[pbudzon]

Is your feature request related to a problem? Please describe.
I'd like to use Autotune to get suggestions about my settings. I'm inputting my data in through Spike and use percentage change when setting TBR, which apparently does not store the "rate" property in NS.

Describe the solution you'd like
Could NS automatically fill in that information before storing it? It knows my current basal so calculating the rate should be fairly easy.

Describe alternatives you've considered
I think a script could be written to back-fill the data, but it would need to use the currently-set profile information (I think? NS does not seem to store profile history?). So if I changed by basal recently, the calculations would not be correct.

Additional context
N/A