Installing 2 encrypted Debians alongside Windows

["coco.20@t-online.de" <coco.20@t-online.de>]

Hi.

Debian 9.2.1 MATE.
LUKS-encrypted via Debian Installer from 9.2.1 DVD.
Current partition scheme: EFI; Windows 10; Debian /boot; LUKS-encrypted
Debian /root & /swap; Unallocated; Windows 10 Recovery.

I'd like to have a second, LUKS-encrypted install of Debian on the
unallocated partition, so that I'll ultimately be able to choose between
booting Windows, Encrypted Debian A and Encrypted Debian B from the
default Grub boot menu.

If I try to accomplish this with the 9.2.1 install DVD, will Debian
Installer be aware of the existence of the pre-existing Debian install
when generating/updating Grub?

Thanks.