as stated at the beginning of this thread it won't be an addition of new algorithms, rather a design of new presets with currently available ones.
The LPX-5 pitch/delay is very simple to recreate on the H-series, using Vsigfile.
It basically consists of a delay w/feedback feeding a pitch shifter>EQ> 2 parallel delays. Delay 2 (left channel) has feedback sent back to pitch input and feeds reverb (ambience).
You can try something similar on Eclipse:
build a preset made of Loop10 > Mshift+Reverb in series.
The first algorithm will be your delay 1 of the Lpx-5. Pitch and delay 2 will be replicated by Pitch 1 and its delay time in the second algorithm. Keep pitch at 0 cents for Pitch 2 in the second algo to replicate delay 3 of the Lexicon unit. It'll get very close to the original.
If you are interested in interaction fx between pitch & delay you MUST check Eclipse Manifold Alpha and Beta algorithms. These can do wonders!