Good idea to add better measuring tools in Photoshop - I know the Ps team is considering that.
As for the need to upload, and the time it takes - Currently, Parfait uses separate storage from the Creative Cloud, so you must always upload your files, but we're going to be moving to a better workflow where you could save your PSDs in your Creative Cloud shared files folder on your local file system. The Creative Cloud app would then take care of syncing them to the Creative Cloud, and when you view them in Parfait, they will be ready and load quickly.
So, I've been thinking long and hard on this one and it seems to me that this is something that multiple teams are working on at Adobe and not necessarily communicating in the manner that will add value to the end users. You've got Edge Code group working on a Live PSD method (where Parfait came from? or that came from?) to inspect and measure PSD files within Edge Code. You've got the Generator team supporting that with their asset-analysis/prep work. The Parfait team developing a web-based service to analyze PSD files and provide feedback.
Parfait is trying to support developers without Photoshop. I get that. That's a very low value proposition though, considering that power of analyzing the PSD file and just saving out a static inspectable file for developers is a better solution – then integrating that with the cloud if necessary to say, hey, check out my published inspectable file. Or, I could save you a thousand hours and just give you a folder with the HTML and assets already in there – because, you know, it's already done.
The point here is that a web-based service is an unnecessary layer between getting value out of design assets in a production capacity, outside of helping developers that will 9 times out of 10 have a close relationship and likely work side-by-side with the designer. When I look at the generated view on the web through Parfait, I see a DIV that contains everything I already want, right now, from my Photoshop file. It's done. There may be more value there for me to inspect things but, there it is right in my browser and all the pieces are in place where they should be.
Integrating with Photoshop and the entire team could be a bear. You could help that by enabling a straight up ZIP download of everything, with the generated HTML code, right from the tool. Also, it would help if the generated HTML code used the actual layer names and details (they're already in the UI layer). I do understand that you are controlling a server-side Generator (or similar) instance to create the actual assets on-demand. That's where a local tool has more value.
Just a thought. If this were in my desktop environment I would use it every day. The fact it's service based means I can't use it, ever, given restrictions on posting or sharing source files outside of a team.
I understand the restrictions you have, and have heard this from a few other agencies and certain other enterprise customers. We're considering what it would take to provide an on-premise version of our service(s), but I can't share anything specific around those plans at this time.
Use the Chrome Dev Tools to take a look at the page that you see in Parfait. Look at the markup and CSS and see if that would be useful to you. In fact, you should be able to save it out of the dev tools to files, if you like. I'm interested in hearing back from you on whether it is useful as is, and if not, what you think would have to change in order to make it useful.