Thanks. The first part I kind of already understood. And the rest helps somewhat.
Does that mean that in older Amigas there no way past a 512KB limit?
And if the later Amigas have 1MB ROM does that mean that an AROS kickstart will be easier to create for them or offer more features?
Are the ROMs shipped with classic Amigas flashable? As far as I know they are not. In other words, if you need a new Kickstart you have to buy new hardware. If you want to use a larger kickstart you buy a Kickstart replacement chip/board that can handle it.
The main issue with the size of the AROS ROM is with the size of Wanderer. There has been talk of creating a Wanderer Lite to get around this issue. Other than that, there are no major components (AFAIK) that will need reworking to make an AROS ROM of a similar size to a classic AmigaOS ROM. For some software, you don't even need a Workbench replacement like Wanderer anyway (such as most games), so for this software the issue of size is not applicable.