Thanks for the recent commit. BTW I just noticed the problem with merge tag not working ALSO applies to EMPTY left fields (i.e. right content not copied). Would commit cover that case? Probably does

, but thought I should mention.
ALSO, while I am here:
FR (Probably out of scope, belongs in separate thread, but I am lazy): ability to save (metadata downloaded) covers into book files. I like to collect covers in my book files, and sometimes alas I find I want both the old and the new cover! Merge covers button?!!?