Dashboard properties can be changed on the PHP server by editing its JSON before loading it into the client.

Decode the JSON, change properties, load.
$reportJson = json_decode(file_get_contents('../reports/Christmas.mrt'));
$reportJson->ReportAlias = 'Dashboard Alias from Server-Side';
$reportJson->CalculationMode = 'Interpretation';

$report = new StiReport();
$report->load($reportJson);
$report->print();

How it works. The template is edited as plain JSON on the server, so any property can be overridden before the dashboard reaches the browser.