I use an even smaller tripod
which is adequate for long exposure AP with the Polarie and FL55ss (may figure a total load of ca 4kg between camera, refractor and tracker). Folding into 40cm is pretty handy for travel.
Sadly the tripod is only available as kit* with a diminutive, but very decent, ballhead (it is perfectly adequate to handle my 66/400ED if tilted at 90°; however the RC2 quick-release mechanism makes somewhat hard to balance the tube, and would not be possible to use a binoviewer or 2" stardiagonal/eyepieces).
Since your tripod is rated for even heavier load, I presume it could serve you well; and in any case, for the sake of lightness, a certain degree of compromise may be worth
*the 1.5kg figure refers to the whole kit, 300g being the ballhead