Accurate emulation of the Saturn will need more a powerful soc and a more sophisticated emulator. Something like Mednafen Saturn requires a pretty potent 4 core i5 CPU, 4th gen at least. That's way beyond the hardware of any mini console so far.
Though SSF was more performant but still more demanding than similar PS1 emulators (which is the most demanding console in the mini collection so far). And i'm not sure such code is good enough for retail. Unless Sega's standards are as low as Nintendo's lately.
Yabause forks are much less demanding. Also less accurate and what not, but they can probably tweak and tune each game in a limited lineup to work as it should. Not that they will use Yabause or Mednafen, just saying if they get emulators in a similar vein. SSF is still more accurate I believe and less demanding as you said, sans the games it has trouble with (if they haven't been fixed, last I tried the SNK fighting games had issues with sprite rendering), but anyway, it just shows it varies by the implementation and development and one emu being demanding doesn't mean all will be.
Something Sega could do to make a Dreamcast Mini stand out is add support for
Sinden Light Gun out of the box and put as many light gun games from console/arcade on it. The Sinden works on modern flat panels displays and could be an easy way to deploy such games.
That'd be pretty sweet, I guess they could do it like Taito's Egret II Mini's trackball/knob/flipper controller, where the main system has normal games and you can get a premium bundle or separately buy the extra and it comes with an SD card or something that has all the relevant games on it.
That said, as amazing as Sega's lightgun games are (even with underwhelming ports like HOTD on Saturn), neither Saturn nor Dreamcast have all that many each sadly. PlayStation systems have way more good ones from different companies even without Sega's top tier stuff (though they put some on PS2 anyway). Dreamcast really only has Virtua Cop 2, Confidential Mission, HOTD2 and a couple dodgy non Sega stuff. Saturn only has Virtua Cop 1 & 2, HOTD, and again various dodgy ones like Area 51, Crypt Killer, Die Hard Trilogy's lightgun part and support for specific portions of other games like Policenauts. I guess they could expand on this a little bit if the Dreamcast mini can also emulate Naomi (1 of course, but I don't think 2 had any lightgun games anyway) with the likes of Lupin the 3rd The Shooting, Ninja Assault and Maze of Kings but it doesn't quite fit.
They should probably do an arcade mini for them instead. Maybe instead of making specific models like Astro City do one with 2D games, one more advanced with super scaler focus (on all the different boards those were done), then Model 1 & 2 level games with lightgun option for the latter two. Of course they have many more amazing lightgun games that require beefier systems, like Virtua Cop 3, Ghost Squad, Operation Ghost, newer HOTD games, they should totally work a deal with Sinden and release them on consoles/PC tuned to lightgun play, not like the recent HOTD remake.
Also so many great Sega games used licenced IP making re-releases harder, game licenses should really apply for that software on any kind of release/port/re-release, as long as it's not somehow an all new experience like a sequel or full remake, it should be allowed with the original agreement.
And of course all these systems also had many great third party games for which they'd have to consult their developers and publishers, like it would be silly to have Dreamcast mini without SoulCalibur (it's still the best version afaik).