I'd really quite like Layout inheritance. I'm imagining a drop-down for the Parent Layout, and maybe we could have different coloured fonts or something whenever an option is the same as the Parent (and thus inheriting).
Still, it's not really that hard to setup and change. Even if you had to use a different layout for every single kind of frame, it's still markedly easier to setup than Pitbull3.
Having separate "New Layout" and "New Layout based on this Layout" buttons might be nice too.
Projectnova, my current layout is basically what you want and it's working awesomely and is definitely possible using a single layout and the horizontal mirror option.
My Player and Target frames have the Cast bar up the top (not the Blank bar, but close enough). It usually has the unit name when no casts are happening. I have actual HP, percentHP, MP and percentMP on the right side of my Player frame, and the magic of horizontal mirroring displays these on the left of my Target frame without any problems.
I attached my WTF file (was forced to ZIP it for some reason).
It's also possible that there is some strange bug with using the Blank bar.
Also, if the only difference between 2 frames is the left-to-rightness or the top-to-bottomness, you can already choose to employ a horizontal or vertical mirror on a per-frame basis. You can use the exact same layout, and just tick the right boxes.
Something I've noticed is that the auras don't honor the mirror settings yet, but I'm actually confused as to whether or not this is a bad thing. :)
Also, I'm having trouble setting elements to be anchored to the Inner Top-Left and the Inner Bottom-Left of frames. It behaves like I've set them to Inner Top-Right and Bottom-Right instead.
Chrnotic, in the Tickets page, you can filter them by Status. By default, "All Open" tickets are shown, which would explain why you can't find yours.
Your Visual Heal ticket has "Duplicate" status. There's no official comment, but it would appear that someone already filed a ticket for something very similar.
Your Statusbar textures ticket has "Invalid" status. After reading this ticket, it appears that you have reported multiple issues within a single ticket. That's very naughty, and not what tickets are for. Each ticket is supposed to be about a single issue. CKK himself has a left a comment against this ticket addressing some of your concerns, so you should look it up.
Remember, this addon has yet to have even a Beta release. And the configuration is markedly different to Pitbull3's. Try to poke about with absolutely all of the settings before deciding something is missing.
Don't take the ticket thing too personally. Remember that it's up to the author to decide if your issue fits into their vision. If you feel strongly enough about your ideas, you can always try your skills at making a Pitbull4 module or something.