I would agree that tilting the speaker backward is the easiest and cheapest thing to try and will most likely be successful. Any adjustment affects a number of variables so it is not that easy to know the outcome. For example, getting a taller stand will not only affect the height/aim of the tweeter, it raises the woofer further from the floor and this will affect the floor bounce effect (the interaction of the delayed wave bouncing off the floor and the direct wave from the driver).
Changing/adding footers will also change the tuning of the system because it will affect how the speaker resonates or whether the speaker will impart more less energy into the floor itself which can act as a kind of sounding board. It is not always the case that reducing resonance sounds better, so it is again a matter of trying out the change. Harbeth speakers are designed by people who believe in working with the resonance of the cabinet rather than trying to kill as much resonance as possible.
Good luck with your experiments.
Changing/adding footers will also change the tuning of the system because it will affect how the speaker resonates or whether the speaker will impart more less energy into the floor itself which can act as a kind of sounding board. It is not always the case that reducing resonance sounds better, so it is again a matter of trying out the change. Harbeth speakers are designed by people who believe in working with the resonance of the cabinet rather than trying to kill as much resonance as possible.
Good luck with your experiments.