This is something I noticed that improved my wordle scores a lot.
The iPhone app on the other hand includes -s plurals in its solution set, which makes for a markedly inferior game (it also has an error in its use of the yellow indication, which also impacts negatively)
Regular pasts in -ed would pretty much restrict you to four-letter verbs that are spelled with a silent E (kite ~ kited); that will be a much smaller class of words than the ones that get excluded by the "s" suffixes.
There is a weird tangential observation we can make here, which is that the plural suffix -s, the verbal suffix -s, and the verbal suffix -t all behave exactly the same way - they are ordinarily zero syllables matching the voicing of the consonant that precedes them, but when that preceding consonant is similar to the consonant of the suffix, they grow an epenthetic vowel (becoming one syllable instead of zero) and become voiced - but the -s suffixes are only spelled with their epenthetic vowel when it exists (compare mats versus masses), while the -t suffix is spelled with its vowel whether the vowel exists or not (compare mopped versus modded).