The very first thing I learned in "bonehead Greek" well over 40 years ago was the non-temporal nature of Greek participles.Are you familiar with Greek aspect? Apparently not, since you are using the terms "past" and "present" in reference to Greek participles, where aspect trumps tense almost all the time.
"The present participle, like the present inf., is timeless and durative. (a) The Time Of The Present Participle Relative. The time comes from the principle verb. Thus in Ac. 4:34, 37 the time is past; in Mt. 6:27 the time is present; in Mt. 10:22, 6:18, 24:30 it is future.” Robertson, p. 891.
This is just more evidence that Smyth has little or no actual knowledge of Greek.