RPGMemes

Now technically the magical restraint that holds the creature doesn’t mechanically cause any particular condition.

Who said it holds the creature? It's created to hold the creature, but I'll decide not to and sell my magical restraint to help offset the costs of the spell.

However it is worth noting that the spell also says the condition to end the spell must be something the DM agrees to AND is likely to happen in the next decade.

In 2014, that was optional. On the bright side, now immunity to aging etc. are straight up effects of the spell, instead of something that happens as long as you're affected by the spell, making it so an elf would only be affected by those secondary conditions if they're affected by those secondary conditions. And also now you can just recast it the next day if they pass the save.

The simplest would be that it breaks if the next coin flipped lands heads. You'll have to recast it a few times, but once it sticks, it's permanent.

You could recast it each time it breaks, but it has a costly component. It's probably cheaper than Clone, except you could just Wish for Clone and get it for free, so not really.

I also notice that this breaks an exploit I had for truely defeating an opponent. In 2014, you could cast Hedged Prison, then destroy the special component, and there'd be no target to use Dispel Magic on. But I think I found another way to do it. First, cast Demiplane, then for 364 days cast Mordenkainen's Private Sanctum inside the demiplane. It can fill up to a 100-foot cube, and Demiplane is only a 30-foot cube, so it fills the whole plane. Then capture your target and cast Stone to Flesh on them (you can do this earlier, but you'll have to be careful storing them). Then you bring them to the demiplane, and have a Glyph of Warding cast Private Sanctum one last time after you leave. Nobody will be able to find them, and even if they could, it's blocked from interplanar travel. As far as I can tell, nothing short of Wish can free them.

To make it a bit more secure, you could True Polymorph them into an object. That way, you can't use Gate to open a portal there. They'd need Wish to grant them immunity to Private Sanctum to actually enter the portal, but they still won't know where to open it. Though if they know the nature and contents, they could use Demiplane.

Another possibility is to use a Glyph of Warding to cast Demiplane so that you can't use Demiplane to open a portal there. Then use Gate to leave on the 364th day with a Glyph of Warding ready to cast the last Private Sanctum.