full access log in laravel 5.8 with session (error bag + flash) data

Question

I'm trying to implement a full access log in a Laravel 5.8 project and that's what I've come up so far: a table named access_logs in a secondary database so than non-relevant log data won't make the db bulky during backup, and custom primary key with no AUTO_INCREMET so can be purged old data without worrying about resetting incremental id while new data is being created. the model is following:

class AccessLog extends Model
{
    public $timestamps = true;
    public $incrementing = false;   // custom id, purgeable

    protected $connection= 'mysql2';

    protected $fillable = [
        'id',   // custom id, purgeable
        'auth_guard',
        'auth_id',
        'url',
        'method',
        'referer',
        'request',
        'session',
        'additional_data',
        'ip',
    ];
}

and the DB writing part in the middleware is following:

$logData = [
    'id' => join('_', [
        time(),
        Auth::user()->id ?? 0,
        rand(100000, 999999),
    ]),
    'ip' => json_encode(request()->ips() ?? ''),
    'auth_guard' => auth()->getDefaultDriver() ?? null,
    'auth_id' => auth()->user()->id ?? null,
    'url' => url()->current(),
    'method' => request()->method(),
    'referer' => url()->previous(),
    'request' => json_encode([
        $this->removeKeys(request()->all(), [
            'password',
        ]),
        $_FILES ?? [],
        request()->headers->all(),
    ]),
    'session' => json_encode(session()->all()),

];

AccessLog::create($logData);

the middleware is registered in the kernel file under protected $middlewareGroups['web'].

now my question is I'm trying to log form validation data (ErrorBag?) as well as flash messages, but it seems those do not exists or saved with the session data (session()->all()), how to include/save those with the log?