A question Cloanto probably wouldn't look too kindly on, but could the rom be edited to add the missing components and be re-burned?
No, there is just not enough room left in the ROM to allow for everyting to fit. The Cloanto ROMs feature updated components which are significantly larger than they used to be in the old 3.1 ROMs, e.g. the FastFileSystem. While the size changes may seem to be modest, they do add up.
Commodore ran into the same problem with the 3.1 ROMs for the A600/A1200/A4000T, and while they managed to make just enough room for the A600/A1200 ROMs, the sizes of the components in the A4000T ROM broke the camel's back, so to speak. Which is why the A4000T ROM dropped the "workbench.library". It's the one single component which is the easiest to "sacrifice".
There may be other options for fitting components into ROM one day. It might just be possible to use data compression, at the expense of increasing system startup times and making more demands on available memory. I did that sort of thing before, for the Picasso IV ROM, except that it loaded the components off the flash ROM into memory only, without decompressing them. But that could be added, it's not that terribly hard to pull off.
The problem being that you need a compression method that saves enough space, a corresponding decompressor small enough not to eat up the gains, and enough memory to decompress the data.