you could pre apply titans kernel , transtions.ini and maybe cut out a few apps to save space and/or replace with other 3rd community apps that were not optimised but that could use hell of a lot of root space. (don't think data can be written to emmc at the same time. but maybe with a custom emmc image as well?) quite a bit of effort. to save X amount of time with each reflash, dont know if many will be that bothered but i did want a custom firmware until i thought about it.