Speaker Spikes Question

I bought some Precision Geek 20mm long M10 speaker spikes with bases to fit to my B&W Speakers that I am refurbing.

The manual for that speaker says that floor mounted the OEM stand has a 9 degree backward tilt. As Precision Geek make a M10 75mm spike I was considering ordering some as punching the calculator if I fit 20mm spikes at the rear and 75mm spikes at the front I achieve roughly a 9 degree tilt.

But I am not sure if this is a good idea, would I hit problems with the speakers or the pads doing this?
 
Another way to alleviate the need to tilt so far might be to raise the speakers or to sit on a lower chair. Just saying. If you need to insert the base for a spike and then load it at an angle and apply vibration, its strength may be tested.