No bp-custom.php has to run from plugins folder.
As much as one would expect functions.php to be too late in the proceedings to set a constant that is read it did/does actually work for me to change my user avatars ??
This issue of being able to effect default ‘stuff’ from themes does crop up from time to time, ideally a method that could ensure things could always be set from functions.php would be great but not sure how or if that is possible with something like Constants which by definition have to be set at earliest opportunity.
