RECOMBINATOR doesnt work. Mostly.

Recombinator is very unfun, unfinished mechanic.

Yet the potential is huge there, even this little detail can save the game at current point, and make it sorta good again, without trying hard.

TO IMPLENET:
- new rune type for items to increase chance to not break (increased % recombination chance)

rune will have 3 tiers, same as others = 50% 150% 300%

so in example with 2 slots on items you can go for max 4x 300% => 1200% increased chance for success.

+1200% is not much at all, considering that it needs 36 BASIC RUNES, the cost of the craft would be huge. So payoff should also be balanced.

This means that anything with chance above 9% would go to 100% for guaranteed success.
And crafts like 0.8% would become at least somewhat viable at ~9%
Most basic crafts at ~50% can be saved by 2 lesser runes.

Greater smithing rune would have drop rate of 2X divine orb.
Lesser smithing rune would be dropping like chance/fracturing orb.

---------Conclusion------------
This idea alone brings CRAFTING into Poe2. Im not sure if making the game fun is against your vision, but this is exactly how to do it.

Do you want to make items on the ground more valuable ? this is how you do it. One good mod is enough to pick the loot.

It will hugely improve/impact SSF.
Currently even the standard mode is too discouraging, so I would not believe that adding crafting to SSF will hurt in any way. If anything it will make the mode viable to many people.

And overall this will not decrease the play time for majority, only increase.
People who already got 'full build' left the game.
People who cant get to that point left the game.

More accessible items can only keep people to play more or even retake the campaign second time for new character.

If you try so hard to increase play time of game, by increasing grind, and completely destroy the fun aspects of it, nobody is going to play it at the end.