“Also all hours from SP to private must be from a full CFI”
That comment is incorrect. See 61.109I as previously posted.
(l) Permitted credit for flight training received from a flight instructor with a sport pilot rating. The holder of a sport pilot certificate may credit flight training received from a flight instructor with a sport pilot rating toward the aeronautical experience requirements of this section if the following conditions are met:
(1) The flight training was accomplished in the same category and class of aircraft for which the rating is sought;
(2) The flight instructor with a sport pilot rating was authorized to provide the flight training; and
(3) The flight training included either—
(i) Training on areas of operation that are required for both a sport pilot certificate and a private pilot certificate; or
(ii) For airplanes with a VH greater than 87 knots CAS, training on the control and maneuvering of an airplane solely by reference to the flight instruments, including straight and level flight, turns, descents, climbs, use of radio aids, and ATC directives, provided the training was received from a flight instructor with a sport pilot rating who holds an endorsement required by §61.412(c).
I believe you misunderstood my post. Once a sport pilot certificate has been issued, the LS CFI is not authorized to give instruction required for the private certificate.
61.413 What are the privileges of my flight instructor certificate with a sport pilot rating?
(a) If you hold a flight instructor certificate with a sport pilot rating, you are authorized, within the limits of your certificate and rating, to provide training and endorsements that are required for, and relate to—
(1) A student pilot seeking a sport pilot certificate;
(2) A sport pilot certificate;
(3) A flight instructor certificate with a sport pilot rating;
(4) A powered parachute or weight-shift-control aircraft rating;
(5) Sport pilot privileges;
(6) A flight review or operating privilege for a sport pilot;
(7) A practical test for a sport pilot certificate, a private pilot certificate with a powered parachute or weight-shift-control aircraft rating or a flight instructor certificate with a sport pilot rating;
(8) A knowledge test for a sport pilot certificate, a private pilot certificate with a powered parachute or weight-shift-control aircraft rating or a flight instructor certificate with a sport pilot rating; and
(9) A proficiency check for an additional category or class privilege for a sport pilot certificate or a flight instructor certificate with a sport pilot rating.
(b) A person who holds a flight instructor certificate with a sport pilot rating is authorized, in a form and manner acceptable to the Administrator, to:
(1) Accept an application for a student pilot certificate or, for an applicant who holds a pilot certificate (other than a student pilot certificate) issued under part 61 of this chapter and meets the flight review requirements specified in §61.56, a remote pilot certificate with a small UAS rating;
(2) Verify the identity of the applicant; and
(3) Verify that an applicant for a student pilot certificate meets the eligibility requirements in §61.83.