There are no Memory Cues in Engine. However, Rekordbox is the only system relying on those. Engine, Traktor, Serato, VDJ & co. all do perfectly fine with the standardized 8 Hot Cues. Personally, I don’t need more than those. You can still use them as mere track indicators, similar to Memory Cues, but even labeled and color-coded. Plus, Engine has always offered the choice between momentary vs trigger behavior (similar to “gated cue” in RB).
Memory Cues are a relic of bygone times, where the high-end CDJs (1000/2000) only hat 3 Hot Cues and the mid-tier CDJs (800/850/900) none at all, just their 10 memory cues. SC5000 has 8 RGB multi-mode performance pads since 2017, which is the way to go imho.
By the way, we have an existing topic about your question already, you might find more answers here: Memory Cues / Visual Markers Feature Request - #20 by kluberboy