Part 61 allows much more flexibility then Part 141 which tends fo be too rigid.
I’ve been Chief Flight Instructor at a 61/141 school and I much preferred Part 61 0 - hero students.
Part 141 does not allow you to fly lessons out of sequence and adheres to a very ambitious syllabus. Lesson redo’s require permission from Chief FI.
Under 61 you can incorporate more and combine lessons, for instance introduce radio navigation much earlier so there is much more understanding and proficiency once the IR starts. Also under 61 all of your time building can be done cross country while the 141 syllabus does not allow this.
Also under Part 61 I’ve combined CPL/CFI about 5-6 times with a 100% succes rate.
Do all your CPL training and checkride from the RH seat and use the same examiner for your CFI.
That saves you about 20-25 hrs of additional flight time. You can be a CFI at 252 hrs.