Everything about that contest is about as below board as it gets. It's a glorified popularity contest and as unethical as it gets. They literally let their staff members, supervisors and anyone else compete in the contest and also JUDGE it.
Also behind the scenes, many of the winners are under an airtight NDA they have to sign to get the prize money because Honeyfeed takes a huge chunk of your novels rights via a contract they require you sign once you win, they don't want anyone to know that tho. They originally had this rule in the general contest rules two years ago "you forfeit all rights to your novel by entering" then they got a shit ton of backlash so they took that out of the public rules but make all their winners sign an NDA with their "Literary Agency". That way they can still snatch the rights on the back end via their "exclusive contract" and no one can legally speak publicly.
So mixing the fact that Kodansha hasn't signed any of the winners, Honeyfeed hasn't invested anything into promoting the winners online to new readers (not even a piece of artwork), and the fact that they take rights from you to get the prize money while having nearly zero verified credibility in the Japanese publishing industry (other than popping up and claiming to be a Literary Agency), I'd say that anyone with actual talent and IP they want to protect should run as far from that place as possible.
That entire operation screams TokyoPop and it's predatory OELM scheme way back when.
J-Novel Club is running a contest this year for light novels which appears to be a lot more above board and they are very clear about rights. Everything with Honeyfeed is shady NDA and "you need to win to find out". Very shady for a new Literary Agent with zero results or track record to bar all its clients from speaking. No reputable Agent would ever ask for one.