Yes, in Proconnect Tax Online, I can click details on a blank interest item. Suppose you have two countries, then you would click two blank interest items, one for country 1, and the other for country 2?

Short answer is Yes.   

Here's the long answer:

Well, if I do one (entering on a blank interest item solely for Part III disclosure) for Country 1, why not for Country 2? 

Yes, I would need to double check it every year to make sure the info is still applicable to both (or in fact, either) countries.  But then, this has to be done regardless of whether the interest item is blank or has description.  Interest income items with zero interest would NOT show up in Part I anyway.

I don't have a lot of those.  Some years ago, a client with Canadian RRSP (who under the old rules made the election to treat it as nontaxable for US) also had set up a Trust in another country.  Form 114's (formerly under an old form number that I no longer remember, something to do with 22.1) had to be filed.  Neither account generated US income.  He passed away several years ago.  Thus, this example has expired so to speak.   (It's still sad that don't ask me if pun is intended.) 

The problem for putting it in General is that for those e.g. @George4Tacks who has a taste for Tacking the Part III info onto a Part I interest income item, they can't do the tacking from General.  If Lacerte put it in BOTH General and as a feature for individual interest income items, it would confuse the heck out of some users.  Then we would have posts here like "Why in the world would Lacerte have input in two separate areas for this?  How do we decide whether to do it in General or in ....  things like that.  Then George would have to explain the flip side of the above....