Future technology

There are limitations to what current technology can do. Research scientists want to get finer control on how DNA sequences might be added to a host cell. Technologies that could offer this sort of control might well result from a merger of highly engineered/modified viruses with micromechanical technologies, modified to migrate to a particular specified N nucleotide sequence in the host DNA for N significantly large to minimize targeting errors, then precisely and efficiently insert the desired snippet in the correct position in the host. Evidently it would be desirable to allow such a device/organism to feed on available resources in the host in order to migrate from cell to cell and perform this process until a significant proportion of host cells had been transformed; it would then be desirable for the device to disable itself. Also it would be desirable for the device to understand when it had finished with a cell (e.g. after levels of a desired protein reach a critical threshold, though this would be perhaps too slow, i.e. movement via measurement of some sort of chemical gradient) so that it could move on. Certainly such devices could not be user controlled for a large population; they would need to be autonomous.
Since DNA sequences vary from individual to individual, and individuals may even be chimeras, also required would be the capability to sequence individual genomes, the ability to target fixes to particular parts of a chimera population, and finally a good understanding of how to avoid disruptive edits- that is, edits that do not disrupt the functioning of some other process in the cell. This requires some level of mastery of the area of proteomics, that is, the understanding of a lifeform's proteome.