From just reading and observation, it appears to me that the likelihood of transmission starts out practically nil until symptoms appear, then begins to build as viral load in the host increases, with a very high likelihood occurring in the hours immediately prior to death, followed by the very highest likelihood of infection being from the body and anything touched by it following death for at least several hours, possibly more.
Yep, it’s all about how much virus is in your blood. From the blood it goes everywhere including salivary gland and sweat pores.