  The classical-dS scenario in the type II string theories proposes to search
for dS vacua of orientifold flux compactifications in a regime where string
corrections to the compactified effective field theory are negligible. We study
a minimal extension of this scenario in which the leading string corrections to
the O-plane/D-brane actions at the 4-derivative order are included but higher
orders as well as string corrections in the bulk are self-consistently
neglected. Our proposal is motivated by a recent debate about dS solutions with
O8-planes which circumvent a classical no-go theorem due to unusual sources
leading to so-called permissive boundary conditions for the 10D supergravity
fields. We argue that such sources do not arise in classical supergravity but
ask whether including the 4-derivative corrections leads to sources that have a
similar effect. However, we find that the 4-derivative corrections do not allow
meta-stable dS in a class of models with O8-planes and/or D8-branes we
consider. We also study related models which in addition contain
O6-planes/D6-branes and find that again no meta-stable dS is allowed, both
classically and including the 4-derivative corrections. While some of the
arguments in this work require the backreaction of the O-plane/D-brane sources
to be small, others are valid including the full backreaction.
