Session rate and number in Billable Time

I may have suggested this before. Forgive me if I have.

Many freelancers work at a sessional rate rather than an hourly rate. Please could BT and Invoice Hour column be modifiable to reflect this.
I attach screen shots of my idea which would involve an radio button , sessinal number box, and a modified column header. The coding mths should be very similar ie Session Number x Rate compared with Hourly Rate x Time.
Hope this makes sense.!
Apologies for the poor art work!!

Screenshot from 2017-11-08 09-21-03|690x387

Billable Time is used to calculate the time you spent on a job and hence Hours.

If you are working by session, why not create a Non-inventory item under Settings and set the Unit Name as Sessions? i believe this should be the approach but that is only my view.

A very valuable feature of Billable Time is that one can add future “sessions” and BT can work as a sort of work diary and a running total for the customer
/client. If the Hour Invoice Column could be edited that would help.

Billable Time is used to calculate the time you spent on a job and hence
Hours. Time can be measured as hours and blocks of sessions or any other
unit of time.

This is already in the Ideas category: Billable Services tab.