I must be missing something but I am having a problem with Edit In. I set the Alternate Editor prefs to create TIFFs but when I select Edit In, select the plug-in and select Edit A Copy, LR creates a copy but it is a psd file instead of a tiff. I included a snapshot of the Edit In dialog which shows the file type of the copy as tiff.
LR 4.3, OSX 10.7.5
What am I doing wrong?
You said you set up the "alternate editor" prefs to create tiffs, is your primary external editor set to save as a tiff? I guess I'm assuming you mean after you edit your image in the plug in (PS) when you save back to LR it saves as a PSD instead of a TIFF? The only thing I can think of is you might have PSD selected in your Lightroom external editor preferences for the primary editor.