No, you can do log-structured BLOBs which essentially given you version control in a simple manner with circular buffers. As for variable-length configs, yes,

No, you can do log-structured BLOBs which essentially given you version control in a simple manner with circular buffers. As for variable-length configs, yes, but you should always be allocating the worst-case (i.e. defined maximum), hence no need for variable length.