I have been using Manjaro for a while now, always pleased, and it never gave me trouble when installing to my LVM when using Thus. When I recently tried to install again to an existing LVM I was disappointed to find there was no longer an installer which supported installing to LVM. Below are the steps for how I was able to install the XFCE edition on an existing LVM.
First, this will not require GUI. You can do this in the terminal, or TTY, either will work.
After booting to the live disk, take a look in /bootmnt/manjaro/x86_64, and you'll find several .sqfs files. You'll want the following 2 sqfs files (this is for the xfce spin, but should be the same on all):
You'll need to unsquash these (unsquashfs /path/to/file.sqfs), and then rsync them to the desired installation location. For example:
rsync -a /path/to/squashfs-root /path/to/mounted/lvm_volume1
Then from here, you'll only need to follow the Arch Installation Guide on their wiki starting from the "Chroot" section onward.
At the mkinitcpio section you'll want to make sure you follow the LVM instructions here:
Then at the mkinitcpio step, the command would be mkinitcpio -p linux44 (or which ever kernel is being used by your image).
The rest should be relatively straight forward.
Hope this helps someone.