Why there's no 'per_period' variables for secondary offer?

There are ‘price_per_period’ options for original & 1st offer price,

but not for secondary offer.

It is really needed, because I set my offerings in Google Play like this:

1. 7-day Free Trial (1st offer)
2. 1st Year 50% discount (2nd offer)
3. And then original price

In this case, 1st offer price is of course Free ($0), which is unnecessary.

But for 2nd offer, there’s no variable for ‘price_per_month’, so the price in blue rectangle could not be presented with 2nd offer's ‘price_per_month’ price normally.

Please fix this issue and implement the new variables as soon as possible.

Thanks.