You mean like the two E’s in “feel” or the two L’s in “fell”? I just tried and it handles them well. Are you aware of the circling technique? When you want to double up on a letter, you briefly circle it slightly. I believe some keyboards let you hover momentarily without circling.
Try it, swipe F-E-L, it should complete to “fell”, then do the same thing again but form a small, tight circle over the E, it should then complete to “feel”. Works for me every time.