iPhone 15 pro camera hardware limits for long exposure

I had understood that there was a 1s hardware limit for image captures on the iPhone. Has this changed with the newest iPhones? For example, with my old iPhone using Night Mode with the native camera app a 30s image is technically a digital simulation; accumulating data from a series of 1s image captures given the 1s hardware limit. E.g. in the metadata for a 30s Night Mode photo at the lower right you’ll see “1s” next to the Night Mode symbol. However, with my new iPhone 15 pro using the main camera, in the darkest settings using Night Mode I’ve seen the value in this field of the metadata increase up to 10s (these are still 30s shots). See the example below. Has the hardware limit been increased? If so, is this capability available to 3rd party app developers as well? I have not seen any documentation on this. The increase, if correct, represents a significant improvement to low light image capture.