Year-end rate conversion is just not a permissible method for conversion, period.  You may have confused that with FBAR and FATCA reporting, which use year-end rates.

Taxpayers are required to use a reasonable method for conversion, which is generally spot rate although average exchange rate may be acceptable if the income is received ratably over that period.  The only other exception is when the business is a QBU.

In PS, I think the only way you can get foreign pension through efiling is to enter that on the Canadian pension page, which works the same way.  Otherwise, Other Income would be a last resort.

In other software like Lacerte/PTO, you do have the option to check it off as a foreign pension unrelated to US services.  It'd then be reported on the Lines 4c and 4d and you will be able to e-file the return.