PCS order: How many leave days can be use while in TDY en-route assignment?

Hi, currently, I am in TDY En-route status and will be done for the training on 09/17/2021. After graduating from the training, I know they give us travel dates depending on where you are going for the next duty station. In my case, I am TDY en-route from CONUS to OCONUS. However, can I use my leave days with the conjunction of travel dates? I want to use leave for 26 days. Since I have 86.5 leave days at this point, I need to use at least 26 days before the new fiscal year approaches and reset the leave time.

For example, On 09/17/2021, I travel back with my POV to the CONUS area, where I departed before TDY in TX. After that, I will clear everything in the area (Rent, housing, Transportation, and such) and spend with my family in the states (try to use the max leave possible). My dependents are still in the area that I left, so I need to pick them up. My report date is 10/18/2021, which is a month later than the graduation date.

I am not a subject matter expert in HR, so I need to know how it usually works in my case. In addition, I already read AR 600-8-10 chapter 8 portion, but I am still confused or unclear about my case. I appreciate that any S1 or an expert knowledge personal in this area can advise on this. Thanks.