MS
Level 2

Guaranteed payments from 1065 for health insurance premiums

We have a 1065 that allows for guaranteed payments of health ins premiums. I have several questions resulting. 
1. with marketplace premiums changing based on income, what is the best way to estimate this for the guaranteed payment. Do you wait till end of year and figure it based on additional premium credit repayment plus any premiums paid monthly? Is there a particular figure on the 1095-a or the 8962 that tells the actual cost of the ins plan? 
2. On the 1040 when you enter the GP from the k-1 and the marketplace figiures, it is hard to tell where TurboTax is then getting the figure on line 17 of schedule 1. You cannot click on it to see data source. If I take the figure on line 17 and back out the GP I am not left with a figure that is close to the premium credit plus monthly ins premium cost. 

Thank you in advance for any assistance.