On ZC 1.5.8a, is there a way to prevent it selecting the cheapest shipping method during checkout?

I have 3 shipping methods for orders inside Australia, in order from cheapest to dearest:
1) $5 flat rate for small items that will fit in a 16mm thick flat box
2) Regular parcel post
3) Express post

So, if I enable the express paypal checkout button which appears on the first checkout page, customers click that and it automatically selects the cheapest $5 option regardless of whether that method is appropriate or not. I have the option to select the cheapest method turned off in the paypal module, but that doesn't help as the cart itself selects the cheapest method by default.

I have read a few threads here regarding this, but they only seem to apply to older versions of ZC, such as https://www.zen-cart.com/showthread....hipping-method

So, is there a way to select a specific shipping method by default? Seems like it would be a good addition to admin to have that option.