Any process that activates or increases the frequency, rate or extent of the progression of an organism from an initial condition to a later condition, occurring in, on or near the exterior of its host organism.
Comment:
This term partially replaces the obsolete term 'positive regulation of growth or development of symbiont during interaction with host ; GO:0075339'. See also 'positive regulation of growth of symbiont during interaction with host ; GO:0044148'.
Synonyms:
related_synonym:
positive regulation of development of symbiont during interaction with host; positive regulation of development of symbiont involved in interaction with host