ZDoom

I'm posting this for the potential people coming from search engines: D4D mod actually implements such an option. Mod can be found here: viewtopic.php?f=19&t=54843&p=967174#p967174. Seems like doing it should be as easy as asking the authors and ripping proper fragment out.

Don't worry about it. Better to have a denied feature request than no request at all.

With this in mind, however, if you need help writing such a thing, I would go to the scripting forum - people are usually very helpful, and this is just challenging enough that i am sure someone would be interested in helping you write it.

Thank you. Sorry for the inconvenience - I'm quite new to Doom and I didn't know how to check on my own.

This can be done with an external mod, and should be. And thus, anything that can be done with an external mod should not become a baseline engine feature. This muddles way too much with the gameplay.

Having played through Doom 2016 recently, I've noticed that a great contributor to it's feel and difficulty is the fact that monsters like Imps don't just shoot at player current position, but they try to predict it's position in the second the missile finishes it's trajectory. Having a feature like that in classic Doom seems interesting. Does it require a patch to the engine, or can it be done as an external mod? I realize that it might be too non-vanilla for the settings menu, but what about a CVAR?