A way to see untranslated series and see which one is the most popular to increase its chances of being picked up

[aej]

I think in large part what decides which series get translated is the decision of the scanlation groups (based on availability of raws, their tastes, etc.). It's probably not that common to see series get translated because of popular demand, mostly because most readers don't look at untranslated series at all (of course there are some exceptions, like Gokushufudou which was picked up because of a popular tweet).
So my suggestion is: a section which has a large list of untranslated series (even just volume covers), tagged if possible, and where users can "vote" / "Plan to read" / put them in a "wishlist" / etc. Those series can just come from mangaupdates (which has a large list of untranslated series + volume cover, some of which are tagged), and some can come from users who just want to see a series translated. Maybe even a system where a group can commit to translating a series to avoid multiple groups translating the same series.

This is probably too much work, but this would probably greatly expedite the process of picking up underrated untranslated series.

 

[MellowV2]

Many scanlation groups take suggestions. So just pop into their discord or email or etc and ask them nicely.

Most scanlators will check Mangaupdates to see if any groups have taken that project before picking it up. But it's not wrong to have more than one group working on the same manga, and it'll create unnecessary drama if a 'dibs' system is created.

 

[Pika]

Oof, having a list of wanted translations by users sounds like scanlators are needed to work for readers without any compensation. I think it's better to send a mail and suggest the series (Like MellowV2 said) rather than "HEY, popular demand here! Translate or off you go!"

Multiple translations are also not really a problem, people can scanlate whatever they want.

 

[ikemen]

it's a valid idea, since many groups would like to do things that will be popular, especially those seeking donations. But I'm not sure if giving an easy way to sway the attention of groups to the wider public(majority of which will be choosing by the cover) will be a net positive for the community.
A test run would be nice. Maybe the staff could restrict voting to manga that already have translated chapters.
The alternative solution is to give groups the ability to make polls in the group page that could decide what they should translate next.