I don't know, but a team of Canadian researchers synthesized a pox virus in 2018. They say, "this is the first complete synthesis of a poxvirus using synthetic biology approaches."
The methodology required was involved. They point out the difficulties dealing with the hairpin telomeres which would also be encountered with smallpox:
However, poxviruses represent special challenges because of the size (many exceed 200 kbp) and the difficulty of cloning features such as the mismatched hairpin telomeres. Poxviruses also cannot simply be recovered from transfected cells, as the DNA is not infectious.
I actually dread what will happen when this would be come as easy as using a 3D printer you can already buy lab equipment on eBay for a fraction of the costs, order CRISP-R kits online and a lot of really weird supervillain stuff like ordering viruses with a “customized payload”.
Right now you still need a pretty substantial lab and knowledge to pull it off but at some point you might be reading on hack-a-day “How I hacked my food synthesizer to produce Ebola..”
I only hope that our ability to defense against such pathogens would advance at least as fast as we commoditizing the ability to play with proteins and amino acids on a molecular level…
I think you're underestimating the difficulty of synthesizing and amplifying a full genome of this size.