But are those slot machines made so they can't go like 10% house edge?
With dice games housedge can go temporarily to 10% or more.
I don't even know if it makes sense to talk about the "house edge" when every result is deliberately manipulated.
The "house edge" is the percentage of the wagered amount that the house expects to keep, in the very long run.
You can't talk about "expectation" when everything is being manipulated.
With dice games, the house edge doesn't change - it's 1%, or whatever it is set to. Just-Dice's house edge was 1%, even though the actual profit was only 0.3%. If the game ran long enough, the actual profit would have got arbitrarily close to 1%.
Shortly before closing the site, I calculated that it would take something like 100 years for the actual profit to get over 0.99% if betting volume carried on as it had been and if results came in pretty much as expected. Of course, it would also have been possible for someone to turn up one day and lose 50k BTC in 5 minutes, putting the actual profit over 1% very quickly. Despite all that, the house edge was always 1%.
Edit: note that slot machines talk about their "RTP" (return to player) rather than their "edge". They return 93% of bets to the players. Not because of the law of large numbers, but because they make sure that's what happens.
Any chance of just-dice or doge-dice coming back?
I'm keeping my options open. I don't want to run them illegally, so would have to run them out of a different jurisdiction, and that seems like a hassle.