My idea is to add a setting for change the basic "effort" for recipes counting or removing time in formula.
This will let choose between the fastest reserch and the cheapest research.
Once you reach high levels and start working on higher infinite technologies, you can find some research to 10.000 and more where others are locked to less than 10 because they require longer times even if cheaper.
There is a chance to add, maybe in the auto research windows, a flag that force the time to 0 and then start researching cheaper over the fastest?

Actually, for what I've checked, less time is chosen first.
The base idea is "if research 1 require less time is chosen first". Then "if 2 or more tecnologies require the same time, the one that ask less science packs is chosen first."
Then why dont let a flag for change the formula in "first the tech with less science packs needed and, in case of a tie, the faster one go first."?
This is the basic idea.
Do you think it can be done?

This can probably be done, although I'm afraid I might not be able to implement it anytime soon. I'm exceedingly busy these days and rarely have time for Factorio. I'll make an issue about it in GitHub so I won't forget it.

Dont worry. I've made a simple request, not ask you for a job.
Take it easy and live your life freely. :D
This is a game and I hope you give it a lesser priority than your real life.
As you see I take it easy too not pressing too much. To be honest, not pressing at all. :P
Take your time and enjoy your life, throught the game if you like it, or throught your real job if you have a goal to obtain, or throught a social goal, if you have... other objectives. ;)

And, another suggestion, show the next research the script will do based on the current setting?
This allow check if this is exactly what you will do or if you have to change something...

I've made it possible to choose "research strategy" in 4.2.0.
I didn't make AR print what the next research will be, though. It requires a fair amount of code, so I left it out this time.

The "cheaper" option doesn't seem to work with infinite research. E.g. when mining productivity and worker robot speed is queued, it doesn't switch to the cheaper one.
Could you add this? Great mod btw

Ah, the strategy option doesn't quite work like that. When you've queued techs then it'll always finish the first one before moving on to the second (an exception is if you've filtered out ingredients required to reach the first queued tech). The strategy rather affects which techs to research first on the path to the queued tech, so if you queue Construction Robotics and select "cheaper", it'll research the prerequisites that requires the least amount of research ingredients first.
However, a possible solution for you is to instead of queuing some infinite research, you can blacklist the ones you don't want to research (at this time). If you have no queued techs then the research strategy will be used again, alternating between the the non-blacklisted tech, always researching the cheaper first.

This did the trick, awesome. Thank you!