Hi Thomas,
As far as I can tell, the translational equations in the Algorithms section of the documentation page 6DOF ECEF (Quaternion) are correct. Whether or not those equations are as implemented in the block itself is another question, but it seemed to be the case after a quick check (though it was confusing because the notation in the block doesn't always match the doc and at least one block name was incorrect).
The block doesn't integrate acceleration to velocity to position, at least not without taking one detour along the way.
The key term is
, which I would describe as the velocity (of the center-of-mass) relative to the ECEF frame resolved in the body frame.

Note that
is first multiplied by DCM_fb to form
, which is the velocity relative to ECEF resolved in ECEF, which is then integrated to
, which is the position resolved in ECEF.









Is there a specific concern about a specific equation or a simulation result that appears to be not correct?