HPD supercharger should not affect your original honda warranty in any way. However, the default factory warranty for a 2011 is likely expired or near expired.
imho if you're going for a 2011 you may want to consider a JRSC or another FI option as you get essentially the same thing for less of your money, with a LOT more options for post-warranty upgrades.
If you're getting 2013, HPD is imo the best option though substantially more expensive than the sprintex, which is also compatible with the CVT iirc - and also may offer more post-warranty upgrades, but you could possibly also purchase the sprintex piggyback and add it to the hpd-tuned ecu.
imho if you're going for a 2011 you may want to consider a JRSC or another FI option as you get essentially the same thing for less of your money, with a LOT more options for post-warranty upgrades.
If you're getting 2013, HPD is imo the best option though substantially more expensive than the sprintex, which is also compatible with the CVT iirc - and also may offer more post-warranty upgrades, but you could possibly also purchase the sprintex piggyback and add it to the hpd-tuned ecu.