LSD=54 akes to ALD-52 (just puzzling a bit though) it is a anlalogue of LSD [AcetylLYsergicDi-ethylAmide]
And gentler, mentally and physically then 1p-LSD or Al-LAD ime. Although I like em all till now. Especially the low / medium doses I recently ben using. Experimented with halving them to light/ medium doses [spychonaut wiki] so 75 mcg instead of 150 1p-LSD.
And felt the effect where actually not that different, but less distracting. Like with Eth-LAD a dose of 40/ 50 mcg could be enough [more potent compared to LSD, about twice as strong] But don´t think that is the one you looking for, sounds quite deep Eth-LAD.
But Lysergides in general are safe to combine with MDMA, just expect a turbulent experience, and keep both dosages low.
Good luck finding out what you acually looking for, but ALD-52 is a good canditate/ gem. dissapeared of my map, but must be out there still.