First off, the project is only two weeks. How many milestones can you fit in two weeks? For some clients, dealing with billing more than a couple times a month can be a pain in the ass. Additionally, you are working on this project as a side gig, so it's probably not a lot of hours. In this case I would be fine with taking the whole payment at the end. Just have the client put the money in escrow. The client could still screw you over, but at least you know it won't be because of a lack of funds.
On the other hand, since this is a side gig you probably aren't on the same feast / famine cash flow cycle that most full time freelancers are on. You can probably afford to be picky. So, if you don't feel comfortable with the client, just look for another project. For a two week project, I would just do half down and half on completion.
I don't bother with giving partial work based on the payment schedule. At any given time my client has access to everything I have done. However, most of my clients are also developers (or have other developers working for them,) so we may be committing code to the same repo.
I have never been screwed by a client in years of freelancing. I have had clients be way late with payments, but they have always been responsive and sincere when asked about getting a payment. If you are getting screwed, then you need to look at your process for selecting clients.
Don't get too caught up with it. These payment schemes are meant for managing cash flow and risk. You probably don't have to worry so much about cash flow, so your main focus would be the risk.
Personally, I'm not concerned about the risk of losing billable time. My concern is the risk of my business going under. If I lose a few days pay, I'm grumpy, but this won't register on my risk radar. Losing out on a payment sucks, but it's a normal part of most businesses. As long as I'm committed to the long term of my business and learning from my mistakes then I can accept the risk of losing billable time. I might hound Joe down the street for that $10 he never paid me back for the rest of my days, but I can accept losing a few days of billable time because my client went bankrupt and can't pay me. So, be flexible and keep your risk management in perspective.