Urban lore has it that some of the "really good acid" in the '60s under the moniker "Orange Sunshine" was actually ALD-52. This is heavily debated and we'll probably never know for sure how much, if any, ALD-52 was circulating.
Most interesting is that even though he was incarcerated, for whatever reason, the DEA never got around to scheduling ALD-52. It's technically still legal.
In order to combat designer drugs, the government put in place the Federal Analog Act which means you could be thrown in jail if you're caught with a previously-undocumented or never-scheduled drug that the courts find is similar enough to a scheduled one. However, this has only been invoked a handful of times (only 2 I can find) and would likely only ever been used against distributors. Bottom line, a recreational user is extremely, extremely unlikely to be nailed on this law.
Lucky for you, there's this massive, above-ground lab in Europe called Lizard Labs https://lizardlabs.eu/ and produce lab grade products. They might as well be the Eli Lily of gray market psychedelic drugs. You can't buy from them directly but they openly list retailers selling their products. If you live in Canada, Europe, or the US, there's a retailer that will ship to you super discretely through the mail. No tor required.
Here's their list: https://lizardlabs.eu/retailers/
I've never had an order seized, lost, or scammed. I mean, it's paper--nearly impossible to detect. People that have lost shipments have generally just had the item quietly seized by customs with no further repercussions. I've used theindoleshop.com multiple times.
Cheers.
As for the Analog Act, the UK's version is presumably watertight (it effectively bans smelling flowers, but not poppers because gay MPs objected to that being banned), but has not been tested AFAIK.
Apparently Hoffman also did invented ALD-25, but the failed defense strategy was from Tim Scully, who operated a lab and distributed orange sunshine for california ..
The website notes that what they have are "NOT for human consumption". Is it safe or is it different than what one would use for recreational purposes?
This may hold at least some water in court.
It's akin to the age-old headshop rule of calling bongs "tobacco pipes" and kicking anyone out that calls them bongs.