I went with the no serialization route and did not design a 8 bit output serialization module. (the accumulator have two RAM blocks and can output two 16 bit numbers at once) I did make a serialization module, but I realized it's up to that arbitrary specs (if the next module can accept 16*2 input, then that serialization is not necessary). So I just connect the accumulator outputs as they are.
and yeah, it's technically done. It's wack, it's bad, but it's done.
Welp I still need to write that paper :P
The total logic elements should be about 3000 more. Since I wrote quite a lot of unsafe code that raised all the warnings, some of the things that the IDE deemed "unnecessary" were omitted.