Best practice for leveraging cfEnv?

Say I am writing an SDK (just suppose…)

Is the following reasonable, and if so, should it be documented as a best practice?

OLD:

 var appEnv = require('cfenv').getAppEnv();
 var someClient = require('Some Random Thing').setup({ credentials: appEnv.getServiceCreds(/Something.*/) });

IMPROVED?

 var appEnv = require('cfenv').getAppEnv();
 var someClient = require('Some Random Thing').setup({ appEnv: appEnv });

implemented within the SDK by:

 … function setup(opts) { 
    if(opts.appEnv && !opts.credentials) {  // if appEnv is available, use it
     opts.credentials = opts.appEnv.getServiceCreds( someRegex );
    }

Any pitfalls? My idea is to reduce the amount of copy and paste user code. User can just pass in appEnv if they have one, otherwise credentials can be supplied.

No file or test is named; start with the setup API and OLD/IMPROVED examples in the issue, then review how cfEnv credentials are currently supplied. Done means reaching a decision on the proposed appEnv option, its pitfalls and precedence, and whether the resulting best practice should be documented.