I've written a patch for replacing hook scripts run upon Solar::start() and Solar::stop() with callbacks. As discussed, this is much more flexible and allows one to call "init" methods such as starting a timer for debugging purposes.
This patch allows normal PHP callbacks and calls directly from a Solar registry object:
// simple function callback.
// call var_dump with one array as param.
$config['Solar']['start'][] = array('var_dump', array('key' => 'value'));
`
// object call:
// call Example_Class::method statically with one param
$config['Solar']['stop'][] = array(array('Example_Class', 'method'), 'param0');
// registry call:
// call method `method` from registry object `key`
$config['Solar']['start']['key'] = 'method';
