New simplified version of Console for PHP. `composer require 1pxsun/console`

composer.json

{
    "name": "1pxsun/console",
    "autoload": {
        "files": [
            "console.php",
            "wordpress-console.php"
        ]
    }
}

console.php

<?php

class console {
	const VERSION = "0.5.2";
	static $instance, $debug, $error, $output, $logs, $timers;
	static function enable($debug = true) {
		self::$debug = ($debug === null) ? in_array($_SERVER["REMOTE_ADDR"], ["127.0.0.1", "::1"]) : $debug;
		error_reporting(-1);
		@ini_set("display_errors", false);
		ob_start(function($s) {
			self::$error && !headers_sent() && http_response_code(500);
			return self::$error ? "<code>Server Error</code>" . self::$output : $s;
		});
		register_shutdown_function(function() {
			$e = error_get_last();
			$toHtml = empty($_SERVER['HTTP_X_REQUESTED_WITH'])
				&& empty($_SERVER['HTTP_X_PHPCONSOLE']) && PHP_SAPI !== 'cli'
				&& !preg_match('#^Content-Type: (?!text/html)#im', implode("\n", headers_list()));
			if ($e && in_array($e['type'], [E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_PARSE])) {
				self::exception(new ErrorException($e['message'], 0, $e['type'], $e['file'], $e['line']), true);
			}
			if (self::$debug) {
				$title = sprintf("%s %s %.1fMB %.1fms", $_SERVER["REQUEST_METHOD"], $_SERVER["REQUEST_URI"],
					memory_get_peak_usage() / 1024 / 1024,
					(microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"]) * 1000
				);
				$collapsed = $toHtml || self::$error ? "" : "Collapsed";
				self::$logs = sprintf("console.group%s&&eval('console.group%s('+%s+')//# sourceURL=Console_%s,_PHP_%d.%d');%s;console.groupEnd&&console.groupEnd();",
					$collapsed, $collapsed, json_encode(json_encode($title)), self::VERSION, PHP_MAJOR_VERSION, PHP_MINOR_VERSION, self::$logs
				);
				if ($toHtml) {
					self::$logs .= "!function(x,p,e,s,o,c){if(x[e])return;else{x[e]=1}c=function(u,a){a=document.createElement('a');a.href=u;return a.origin===window.location.origin};x.phpConsoleEnabled=1;s=x[p].send;x[p].send=function(){var _=this.onload;this.onload=function(){if(c(this.responseURL))eval(eval(this.getResponseHeader('x-phpconsole')));_&&_.apply(this,arguments)};return s.apply(this,arguments)};o=x[p].open;x[p].open=function(a,u){var r=o.apply(this,arguments);c(u)&&this.setRequestHeader('x-phpconsole','1');return r}}(XMLHttpRequest,'prototype','_phpConsoleActivated_')";
					self::$output = sprintf("\n<!-- PHP Console -->\n<script>%s</script>", self::$logs);
					print(self::$output);
				} else {
					header("x-phpconsole: " . json_encode(self::$logs));
				}
			}
			@ob_end_flush();
		});
		set_error_handler([__CLASS__, 'error']);
		set_exception_handler([__CLASS__, 'exception']);
	}

	public static function error($severity, $message, $file, $line, $fatal = false) {
		if (error_reporting() & $severity) {
			$type = in_array($severity, [E_WARNING, E_COMPILE_WARNING, E_USER_WARNING]) ? 'Warning' : 'Notice';
			self::message(['PHP ' . $type . ': ' . $message], $file, $line, 'info');
		}
		return false;
	}

	public static function exception($e, $fatal = false) {
		error_log($e);
		self::$error = true;
		$message = sprintf("%s: %s\n%s\n", get_class($e), $e->getMessage(), $e->getTraceAsString());
		self::message([$message, $e], $e->getFile(), $e->getLine(), 'warn');
	}

	static function message($var, $file, $line, $type = 'log') {
		if (!self::$debug) return;
		eval(sprintf('$var=%s;', preg_replace(
			'{([\w\\\\]+)::__set_state(\(array\()}',
			'$2"__class__"=>"$1",',
			@var_export($var, 1)
		)));
		self::$logs .= sprintf('(function(){function c(o){if(o&&/j/.test(typeof o)){o.__proto__=null;for(i in o){o[i]=c(o[i])}}return o};for(var i=%d,s="";i--;s+="\n");eval(s+"console.%s.apply(console,c("+%s+"))//# sourceURL="+%s)})();',
			max(0, $line - 1),
			$type,
			json_encode(json_encode($var)),
			json_encode("file://" . $file)
		);
	}

	static function log() {
		$t = debug_backtrace();
		for ($i = 0; isset($t[$i]) && (!isset($t[$i]['file']) || $t[$i]['file'] == __FILE__); $i++);
		self::message(func_get_args(), preg_replace("{[:'\s]+}", "_", ($t[$i]['file'])), $t[$i]['line']);
	}

	static function time ($id) {
		self::$timers[$id] = microtime(true);
	}

	static function timeEnd ($id) {
		if (self::$timers[$id]) {
			self::log(sprintf("%s: %0.3fms", $id, (microtime(true) - self::$timers[$id]) * 1000));
		}
	}
}

wordpress-console.php

<?php
if (function_exists("wp")) {
	remove_action("shutdown", "wp_ob_end_flush_all", 1);
	console::enable();
}