Not sure how comparable they are since I never used Monodraw due to not running MACs, but there is https://asciiflow.com/ and https://monosketch.io/ which I usually use. The latter is using some advanced UTF8 characters and when trying to get it incorporated for my personal blog, I had to use their specific monospaced font from their repo, as otherwise lines wouldn't line up correctly.
Hmm, staying with iSCSI. You should create one large LUN that is available on each node. Then it is important to mark the LVM as "shared". This way, PVE knows that all nodes access the same LVM, so copying the disk images is not necessary on a live migration.
With such a setup, PVE will create LVs on the same VG for each disk image. So no handling of multiple VGs or LUNs is necessary.
That should have been possible for a while. Get the block storage to the node (FC or configure iSCSI), configure multipathing in most situations, and then configure LVM (thick) on top and mark it as shared. One nice thing this release brings is the option to finally also have snapshots for such a shared storage.
In case the author reads this: instead of `losetup` you could have imported the image with `qm disk import VMID path/to/source TARGET_STORAGE`
It would then show up as unused disk in the VM config to be further configured :-)