In the past, if you ran an appserver as ZEO client with a persistent
cache, the startup logic prevented products from being loaded.  This
was a hack that got baked in via the weird interaction between the
FORCE_PRODUCT_LOAD and ZEO_CLIENT environment variables and was carried
over into Zope 2.7 by inertia.  Now they have nothing to do with each other
and can be specified independently.