Sorry I missed seeing this - I rarely browse new issues unless they're "Windows" tagged.

Reading what's in master, I don't *think* there's any regression in the main case, since the values from pathconfig override config and AFAICT they aren't used in between:

    if (pathconfig.isolated != -1) {
        config->isolated = pathconfig.isolated;
    }

Haven't looked back at 3.7, but I haven't heard of any issues coming up here from people I know who have shipped this (though they might have been using SetPath to override it all anyway).

All of this could become irrelevant though if we add support to other platforms for ._pth files :) (yes, it has been requested)