The AFAT has הִתְבּוֹנָנוּ the word at the end of Isa 52:15 morphologically tagged as first person plural (which is wrong). The BHS correctly has it as as third person plural. This error exists in both Logos 3 and 4. I reported it as a typo.
BHS:
verb, hitpolel, perfect, third person, common, plural
AFAT: verb,
hitpael, middle, suffixed (perfect), plural, common, first person