First a bit of background on the problem I'm trying to solve. I have a number of data types that select nodes as part of their configuration (a number of content pickers and some custom controls). It works great for single site installations, but breaks down for multi site installations, as each site has its own version of the node. I've already setup some logic to map the nodes to their equivalents in the other sites, but I'm running into a performance bottle neck when I go to update the configuration settings in the SendingContentModel event. I currently do a basic string search and replace for "guids/ids,"but this causes each node to take a couple minutes to load, which is obviously a poor experience.

Any suggestions on how to improve performance? My current idea is to use a LazyCollection to gather mappers for each data type so that it can directly map the desired property instead of searching through a bunch of text (similar conceptually to the mappers in uSync). Below is my current code.

private void EditorModelEventManager_SendingContentModel(HttpActionExecutedContext sender, EditorModelEventArgs<ContentItemDisplay> e) {
    var target = e.Model;
    int rootId;
    if (target.Id == 0) {
        if (target.ParentId <= 0) {
            return;
        }
        var node = _contentService.GetById(target.ParentId);
        rootId = int.Parse(node.Path.Split(',')[1]);
    }
    else {
        rootId = int.Parse(e.Model.Path.Split(',')[1]);
    }
    var mappings = _configMapperService.GetMappingsByRootId(rootId);
    foreach (var variant in e.Model.Variants) {
        foreach (var tab in variant.Tabs) {
            foreach (var property in tab.Properties) {
                if (property.Value != null) {
                    var type = property.Value.GetType();
                    var stringValue = JsonConvert.SerializeObject(property.Value);
                    foreach (var mapping in mappings) {
                        stringValue = stringValue.Replace("\"" + mapping.Source.Id.ToString() + "\"", "\"" + mapping.Target.Id.ToString() + "\"");
                        stringValue = stringValue.Replace(":" + mapping.Source.Id.ToString(), ":" + mapping.Target.Id.ToString());
                        stringValue = stringValue.Replace("umb://document/" + mapping.Source.Key.ToString().Replace("-", ""), "umb://document/" + mapping.Target.Key.ToString().Replace("-", ""));
                    }
                    property.Value = JsonConvert.DeserializeObject(stringValue, type);
                }
                if (property.Config != null) {
                    var configString = JsonConvert.SerializeObject(property.Config);
                    foreach (var mapping in mappings) {
                        configString = configString.Replace("\"" + mapping.Source.Id.ToString() + "\"", "\"" + mapping.Target.Id.ToString() + "\"");
                        configString = configString.Replace(":" + mapping.Source.Id.ToString(), ":" + mapping.Target.Id.ToString());
                        configString = configString.Replace("umb://document/" + mapping.Source.Key.ToString().Replace("-", ""), "umb://document/" + mapping.Target.Key.ToString().Replace("-", ""));
                    }
                    property.Config = JsonConvert.DeserializeObject<Dictionary<string, object>>(configString);
                }
            }
        }
    }
}