You are correct, 'Impulse #1 was April 1995. My bad.
Wikipedia gives Max Mercury's first appearance as May 1993 in Flash Vol #2 # 76.
https://en.wikipedia.org/wiki/Max_Mercury
[He first appeared in Quality's National Comics #5, cover dated November 1940, as Quicksilver.[1] Comics historian Don Markstein calls Quicksilver "probably the first imitator of the Flash's super-speed schtick.[2]
Almost nothing was revealed about that character except that he possessed super-speed and his secret identity had the first name "Max"
Link to the book:
National Comics 30