Two points to bring up with your NAA:
LIFUS does not have to be done with a TRI. You can nominate Line Trainers if you have other suitably experineced Captains.
For the inexperienced crew criteria, AMC1 ORO.FC.200 (a) paragraph (b) says:
(b) A lesser number of flight hours or sectors, subject to any other conditions that the competent authority may impose, may be acceptable to the competent authority when one of the following applies:
...
(5) the aeroplane has a maximum take-off mass of less than 10 tonnes or a maximum operational passenger seating configuration (MOPSC) of less than 20.
I know of operators who have got their Part D approved with the 10 sectors and no hours requirement under this provision.