[plt-scheme] Question about building after svn update?

I've just completed my first `svn update plt', which went smoothly.

My directory structure looks like:

/source/plt - my checkout directory for the plt trunk
/source/pltosx - the original build directory

When I originally built the trunk for the first time, I used
configure --enable-origtree so that I'd be able to later copy the plt 
directory into my /Applications directory, where I had always kept PLT 
software before.  This worked out fine.

My question now is, can I safely do another build, from a clean directory, 
using the same --enable-origtree option, so that the build process takes 
advantage of those binaries that are already buiit and don't need to be 
rebuilt?   In other words, I would:

$ cd /source
$ rm -R pltosx
$ mkdir pltosx
$ cd pltosx
$ /source/plt/src/configure --enable-origtree
$ make
$ make -install
$ cd /source/plt/bin
$ setup-plt

And then copy the /source/plt directory over the existing 
/Applications/plt directory.

Assuming the above would work, I'm hoping that my preferences file will
remain unchanged now that I'm coming from 
version 369.10-svn28apr2007 [3m].  The problem with the default colors 
was just a one time thing when I upgraded from 369.8 to 369.10 as I 
understand it.

These must sound like really lame questions, but its my first time after an 
svn update, and I don't want to mess it up.

All comments welcome.

--kyle
airfoil at bellsouth dot com