OSU Food Science Department did a little testing of the Presto Digital Canner and found it followed USDA protocol and procedures for pressure canning.   They have not at this time finished all the research and published the results however they did not have concerns about the safety of the canner,  if Presto's recommendations were followed.
Below is a statement on the canner that was published in the new Pacific Northwest Publication on Pressure canning.
 https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw421.pdf 

Digital Electric
Pressure Canner
National Presto Industries recently released a
digital electric pressure canner in the marketplace
called the Presto Precise Digital Pressure Canner
(Figure 13). The canner was developed specifically
to follow the protocols and procedures established
by the USDA for the safe canning of low-acid foods.
The digital electric pressure canner is not a
multicooker and is designed for canning only.
Directions for operation of the canner should be
followed to achieve the conditions necessary for
the pressure-canning process. To date, Cooperative
Extension has not conducted independent testing
of this product. Contact Presto Industries for addi-
tional information on research and testing protocol.
 To my knowledge there has not been huge safety concerns with the Presto Canner however the other multicookers such as the Instant Pot do not heat up and cool down to meet the research guidelines to be safe.  
Hope that answers your questions.  Sorry about the font changing.  No clue what I did.

Thanks for using Ask Extension
Nellie Oehler