1. Boss every 5th, 7th, 8th or 10th floor
Killing random enemies is fun, but there's no other reason to stay in the SO after zone 8 or 16. Also the only thing that changes is the tile and enemy type, and i guess that adding Boss every now and then would improve the dynamics of this mode
2. A little resources every here and there
As i said earlier- there's no reason to stay in SO after zone 8 or 16. And the only reason to even go there (as for now) is exp, focus, khora/vandal weapns or radiant relics (and pure fun, obviously). And it's still worse exp farm than Hydron.
3. Make score useful
As fore now score is... pointless. Ok, i got 500k, 1m, 2m points, but what can i do with it? What if we got some extra rewards for our score? If we got some special items for S rank?
4. Just chage the grades... just do it
It's literally impossible to get anything outside of A+ or S. If you leave on purpose after zone 8/16, it'll give you S. If you fail it's A+. It makes those grades kinda pointless, because they don't say much. Maybe implement higher grades, like S+, SS or SSS (like in devil may cry :P)
5. Standing for playing SO
And once again- there's no longer-period gain in this mode. What if we got some standing from it? If not for the new Syndicate, then for the Simaris one. Maybe it would be calculated based on the score, for example 500k points=1k standing?
And i guess, it'll be the same as with Eidolons- we'll have to wait a little bit, and DE will 'fix' this mode, or make it more fun. But as for now, it's a good fun for an hour or two. Or when you're bored.