Some of my template guides are over 1/2" long. If you have template guides that are fairly long, then it could be done, but care needs to be taken when mounting the router. When the template guide adapter is installed in an OF1400 router, you can no longer use the centering disk of the CMS table that positions the router centered in the table. Without the centering disk, I fear that the router could move as you use it, and if it moved enough, it could loosen the clamping dogs. Maybe I'm just paranoid, though. If you were going to try this, I would recommend placing ether a thin rubber sheet or double-sided tape between the router and table to prevent it from slipping.
On the other hand, you could take one of the throat plates and enlarge the hole enough to accept a universal template guide. But this would be a little iffy because there is less of a guarantee that the guide would be perfectly center on the bit location. The centering disk has a little play in it, which normally isn't a big deal, but would be for template routing.
