Workflow for using proxies and AVCHD

Question

I'm working on a 6 camera mulitcam project of a theatrical performance and I'm using Premiere CC.  The footage is all spanned AVCHD from Canon Vixia's.  My machine is pretty good but no way is it going to play 6 streams of AVCHD at once (I've done 4 and that was pushing it!). 
I've done a little searching on the forum and found this post:
http://forums.adobe.com/message/4877276#4877276
In particular, Fuzzy says:
The workaround is the following:
- create a folder for your proxies next to the folder containing original footages and name it e.g. AVCHD.Proxies;
- transcode your MTS files into MPEG2 ones with the same file names and MTS file extention (or run Batch Rename in Bridge after transcoding with MPG file extention);
- close your PrPro project, created out of original MTS files;
- temporarily rename AVCHD folder containing original MTS files to e.g. AVCHD.Sources and AVCHD.Proxies to AVCHD;
- open up PrPro project and enjoy: all your original AVCHD files are now linked to MPEG2 proxies.
When you're done, reverse rename folders.
This idea appeals to me but I've got a question.  My files are all spanned AVCHD.  It seems, in his example, that each .mts has a corresponding mpeg2.  With my spanned clips, how will Premiere know how to put them together properly?  I don't really mind if there is a one frame drop between the mpeg2 clips but will this majorly screw things up when I swap the proxy footage out?
Is there a better way to do things now, one year on?
Thanks in advance!

Answer 1

Hmmmm... still having problems.
I got back to work this morning (having spent most of the weekend and yesterday raking leaves) to find that all of the mts have successfully been transcoded into mpg clips.  I added a new STREAM folder, moved the clips and changed the file extension to .mts.  So far so good.
I decided not to stitch the spanned mts clips first because I'm on a Mac and I haven't found a good (free) stitcher.  I have a nice Windows one that I like but i didn't have the time to move the clips to a Windows machine, stitch them and then move them back again.  This may still need to be done because I'm faced with a new problem.
When I go into Premiere and try to import the mpg clips (now hiding under the .mts extension) I get the error "The file has an unsupported compression type".  This happens if I use the regular import OR the Media Browser.
Any ideas?  I compressed these in AME using the default "Match Source - Medium Bitrate".  I used the H.264 format, not the MPEG2 format thinking that Macs like H.264 but I wonder if this is the problem
Thanks for everything, by the way.  You've been more than helpful