Custom asset downloading

Hey

I'm working on setting up a build flow for a series of projects where a web build is run in a custom browser where http requests are not available. The assets has to be downloaded through an asset loader unique to this platform.
I am currently working on tiny v0.22 as we will likely need the 2D package.

I am able to edit the .js file that is output in the build and modify the calls to XMLHttpRequest and get builds to work on this platform but this is not really a feasible way to do this as it has to be done for each build. I could make a script for it but this will most certainly break when tiny is updated.

I would like to be able to do this in a more intelligent and robust way ideally as a part of the build process.

So is there a way to customize how Tiny web builds loads assets?
Any pointers to related resources or information on were in the build process these calls are inserted and how/if that part can be accessed is also greatly appreciated.

Thanks