Robert, First off thanks for listing all those links in reply #4. After some reading I still could not quite figure out what lead to the "design decision" to not support a 'home=partition/directory' style boot code. Nevertheless you make up for it by your later statement:
IMHO having two "home" directories and/or two "opt" on a single physical hard drive partition is "messing" up any Linux distribution. In fact I would say that it would be heresy.
I suppose that there are ways to really make a mess with having multiple 'home' directory structures. And I accept that for the "average" user (in particular to those new to Linux in general or TC in particular) this could be almost a "dangerous weapon".
OTOH it is my personal believe that the use of '/opt' in TC is not quite in line of what I've come to expect after using other distributions. I might have also spend to much time on larger Solaris production systems and have hence not expected to see system-wide setting and configuration files in '/opt' (instead of somewhere in '/etc'). So with that "baggage" I personally might go as far as to consider '/opt' to be "mis-used" by TC. But this is not the point as I had already pointed some of it out
a while ago I've now come to expect that historically evolved conventions are not to be questioned, even though that arguments to consolidate, simplify and unify some code could be made.
My main point would be that TC prides itself to be a toolkit to "Build it your way". It would be my view that similar boot codes should support similar functionality. I don't read it that the intention of the OP is to throw everthing over board. So I interpret reply #6 a bit as "letting off some steam". What I'd find attractive would be something along the lines of reply #7, that is the chance to "isolate" TC in any area of a pre-existing EXT[2-4] file system. The point of using dedicated filesystems is that over the years I've always come to regret my choice of sizing. After a while something has always been either to large or to small. So not having to comit to a particular partition size but rather co-use (in a "clean-cut" way) a larger existing one is something that I'd value highly.
Most of this argument might be a matter of personal taste or opinion to which degree something "conflicts" with something else. I personally have the hope that using the 'tcvd' boot code might be a suitable alternative to "persistent home and opt embedding". I would just have to find more time to give it a serious crack ...