Yes, for FTC, PTO is not the greatest in many ways, especially when it comes to more complicated cases, although it's still better than PS and many other professional tax software out there.

I think the problem with F.1116 is that Lacerte/PTO follow what's on F.1116 but there's no reference on the Form or the instructions for 1291Tax.  Intuit should really have referred to §1291 and Prop. Reg. §1.1291-5.

PTO (and even Lacerte) doesn't allow for adjustment or override for Line 20 of F.1116.  The only way is to adjust the numerator on Line 16.  You can make it exact, down to the dollar for the most part.

Here's how it will work out in your example:

• First of all, we'll assume you've already taken care of prior year excess distribution tax, if any, on F.8621.
• 1291INT will not affect F.1116 as you pointed out.
• Ratio of Regular Tax to Total Line as shown on Line 20 is 90.[social security number removed] % (10,000 / 11,000)
• Assuming all your client has is Passive income and no US-source income at all (to avoid getting into discussions about ODL), the taxable income for the Passive basket on Lines 7 and 17 of F.1116 should, theoretically, be the same as the worldwide taxable income on Line 18.  That's why PTO thinks 100% of the entire $11,000 on Line 20 should be offset by the $13,000 Foreign Tax Available for Credit.
• Let's assume the amounts on Lines 7, 17, and 18 are $50,390.  You will then enter an adjustment on Line 16 (as you would for SLL/OFL/ODL) for negative 4,581 ($50,390 x (1 - 0.90909090909)).  This will reduce Line 17 to $45,809 ($50,390 - $4,581).  This will then limit the FTC to $10,000 ($45,809 / $50,390 x $11,000).
• The result is $10,000 Regular Tax + $1,000 1291TAX - $10,000 FTC + $50 1291INT.

Not ideal but that's the workaround until Intuit feels it is important enough to fix Lacerte/PTO (which is unlikely given the number of similar questions we've seen here).  For a lot of folks, this may not even be material provided their clients are not in a high tax jurisdiction and it is unlikely there'll be FTC carryback even when there's excess limitation.