If your HP laptop is new, didn't it come with windows? If so, it shouldn't have been necessary to create the /boot/efi folder with gdisk. It would have been created when HP installed windows onto it. UEFI has one /boot/efi folder for all operating systems installed onto it.
I'm sorry, but, the last siduction install onto UEFI I did was a few years ago. So, I haven't looked at the siduction installers ability to install on UEFI in a while. Although I do remember being able to point the installer to /boot/efi during the installation, and, was able to complete the installation successfully. FYI - One doesn't use mbr at all on a UEFI enabled computer. Could you be having trouble because you wiped windows off of the disk and are starting fresh?
There are actually 3 Boot Managers/pointers in a UEFI box. The first one is contained in the UEFI bios (yeah, I know it's not really called a bios, but, for lack of a better word), this is what you see when first booting in UEFI mode. The second Boot Manager/pointer is on the disk in /boot/efi/efi. This is where UEFI points to the distro/OS chosen at boot up time. The third Boot Manager will be Grub. So, one does not use Grub to chose the distro on a multi boot UEFI machine, one uses the UEFI bios for that during start up. As far as where the Boot Manager (grub) gets installed, it gets installed to the root partition.
A few years ago, I started this thread:
http://forum.siduction.org/index.php?topic=4254.msg37957#msg37957 to help with installing to UEFI. I'm sure it may be out of date a bit, but, the part that explains what happens when using the siduction installer may be helpful. The comments in that thread also have useful links and comments that may also be helpful.
Hope this helped. If not, provide more info, and you'll get more specific answers.
BTW - If anyone see's errata in this post, please comment. Except for my main machine, all my other boxes still use mbr, and, the siduction installer works great on them. Unfortunately, I haven't updated the UEFI box since July, and, may have to do a fresh installation, so, I'm also curious about the state of the installer when using a UEFI enabled machine.