it sort of worked for MBR, it could create new partitions and stuff
defragmenters yeah I have no clue but partition tables are basically editing just some data on the disk thats in a structure so its not THAT hard, just annoying cus MBR has like 16 forms and shit which most of them aren't rly used and stuff
GPT is harder but doesn't seem that hard either i suppose, and at least it doesn't need to know what the fuck CHS addressing is (I still dont fucking know how to calculate that on SSDs so I just ignored it cus kernel or whatever can figure out the MBR record size from the LBA and logical size
its kinda fun, even tho it would not work for sure im too stupid for that