Selection Plugins: DefaultValueListManager depends on virtual content tree which is no longer used in 7.8

I think I discovered an incompatibility with 7.8 in the Selection
Plugins. It concerns the HST part to retrieve values from value lists
in the site.
When specifying a relative path to the value list document, the class
DefaultValueListManager [1] tries to traverse up in the tree to find
the content base node. It depends on the node name "hst:content". This
doesn't work in 7.8 because the virtual trees are no longer used (see
[2]).

// move up the bean tree until no more regular bean, check
hst:content
// to avoid a warning in getParentBean implementation
HippoBean siteContentBaseBean = hippoBean;
while (!siteContentBaseBean.getPath().endsWith("hst:content")
&& (siteContentBaseBean.getParentBean() != null))

{ siteContentBaseBean = siteContentBaseBean.getParentBean(); }

The object "hippoBean" in this case is passed as a method argument.
Probably it is used because the HstRequest is not available and the
site content base bean cannot be determined?
I want to fix this but is it possible to keep the same implementation
but recognize the content base node in some other way?
Or should we change the API and always require the site content base
bean to be passed, so the traversal is not necessary?

BTW this bug does not occur in the Selection Plugins demo because it
uses an absolute path to the value list (see [3]).

Thanks,
Niels

[1] https://forge.onehippo.org/svn/selection/selection/trunk/hst/src/main/java/org/onehippo/forge/selection/hst/manager/DefaultValueListManager.java