Customzing Luks encryption prior to installing Manjaro

Hi,
I am new to Manjaro (or any arch based system) I'm used to ubuntu/debian so I may have some of this backwards or completely wrong. I am performing all this in a virtual machine, to avoid any data loss on my main system. I'm using the Manjaro-KDE-Stable-18.0.4 iso

What I want to do is be able to install Manjaro with luks encryption on the main / partition (I don't care if /boot is encrypted, would rather not as I dont know if grub supports luks2). I want to customize the encryption parameters such as using luks2 with argon2id as key derivitation and custom iterations, some computers I have that are very old but usable make such smaller iterations its considered insecure to begin wtih but for additional security even on modern hardware I prefer to up it something I can handle concerning unlock time.

Usually in Ubuntu live installer i'll open terminal and use kde partition manager to format the main drive as gpt with 1gb partition fat32 for /boot, 1gb for efi system and 3rd ext4 for /. I would afterwards using terminal and enter: sudo cryptsetup luksFormat /dev/sda3 -M luks2 --pbkdf argon2id --iter-time 5000
The iteration count would of course be different depending on what hardware I'm on at the moment, after this I would use cryptsetup to luksOpen it, in this cause using main as device mapper name.
The installer for manjaro at this point wouldn't recognize anything, as installing directly to /dev/sda3 would obviously not work, so I use pvcreate and lvcreate commands to create the neccesary physical volumes/volume groups for thie unlocked luks volume. The installer detects this, I can choose the /dev/vg0/root one and click format, ext4, and mark it as /, then chooise /dev/sda1 for /boot afterwards during install it basically just gives me an error that it is unable to remove this volume group for root and from terminal using fdisk -l I can see the device mapper is not longer there, it some reason unmounted it. This whole process is something I do everytime when installing ubuntu based os, to customze luks the way I prefer but something here seems like I may be missing something or doing something wrong as this is arch based, probably a lot different.

Know what I may be doing wrong?

Thank you.

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