First, the obvious caveat: Every league is different. You’re ultimately the expert here because you know how your league-mates tend to draft, which players they’ll be keeping, how active they are when it comes to in-season trading & what positions they tend to value most, which players will be available to draft, etc…
I’m assuming you’d have mentioned if this were a 2QB / Superflex. If the other members of this league tend to draft QB’s early, roster multiple QB’s, and/or you don’t feel there will be many good options available for you to draft at QB - then I think Dak in the 11th is defensible. Especially if this is a 10 or 8 team league. I love Dak’s weapons this year & think he could put up big numbers.
That said, I’d probably still lean towards keeping Sanders & Ekeler. Deebo’s injury makes him too risky, there are too many unknowns about Mostert when compared to your other RB options, and the crazy WR depth this year reduces Parker’s value.
If you do feel like the league conditions make Dak someone you need to hold on to, I think Sanders in the 4th would be my 2nd keeper. It’d have to be a full PPR for me to take Ekeler over Sanders - even with the 2 round price difference.
Hope that helps!