In the case of a single monopole mounted with its base at earth level,
adding tilt to it makes very little difference in its gain at
elevation angles up to +60 degrees or so, at any azimuth. It does
partially fill the elevation null at the zenith produced by the
vertical monopole, as well as to produce a small amount of h-pol
radiation over most of the compass.

Modeling this in NEC for a 1 MHz, 1/4-wave, straight monopole by
moving its top 10 meters out of plumb changed its peak gain by about
0.01 dB compared to the untilted version, at any azimuth.

RF