The last update I saw in 2017 for Tengai Makyou Zero is that it's still pretty much in the same stalled position it was a decade ago. Nothing is going to happen until a programmer is found who is willing and able to insert the translation.
There was a recruiting drive for the project on romhacking a few months ago, resulting in programmer(s) and an artist volunteering. There have been page-and-pages of updates and screenshots, and the translation is now supposedly close to finished.
That's awesome! I have to say though, it is kinda sad that the first Tengai game to be fan translated is some weird f*cked up SFC thing, the 4th game. However, I'm sure the way things are going with PCE translations these days I suppose it's only a matter of time before I'm hearing "Welcome welcome, quack quack!" re dubbed into English.
Ku wa ku. Ku wa ku.