"...I envisage that the "scientific front-end" we want on Hive won't auto-conceal (i.e. censor) content merely because of downvotes."

Science publishing is all about money. Grants flow to those that publish, and the ability to censor facts dispositive of ideologies, and interpose fake news, is perhaps the signal feature of the extant totalitarian technocratic tyranny being imposed globally. Any front end only rides on the base layer, and Hive is a pure plutocracy. You can prevent the greying out of posts in a front end, but you cannot eliminate flags that require nothing more than stake to fly.

Hive has capabilities latent within it that enable it to become a governance mechanism for voluntarist communities, both geographically localized and dispersed. However, the financialization of it's features have produced #trending and the previously mentioned user retention failure, perhaps the worst in the industry. No one supports eliminating the burgeoning censorship of published research that increasingly eliminates factual scientific information, even as history itself is being purged by scouring the internet of historical facts, and discouraging the publication of scientific fraud that today comprises the bulk of peer reviewed papers in even the most respected journals, just as Goolag's Gemini has been so deranged by it's training that it all but refuses to produce an image of a white man, and replaces historical actors with various flavors of racially preferred peoples, more than I, but the facility with which promotion and discouragement of content, including peer reviewed research, by nothing more than money will be a hazard you will need to navigate.

I hope to encourage you to succeed in this endeavor, and not misapprehend the real impediments to success as have so many marketing efforts before that have caused them to crash and burn without achieving anything they set out to do. Political ideologues control immense pools of capital, not only on Hive, but globally, and you will be sadly mistaken if you just assume they won't deploy it to suppress information on Hive. They have been since 2016, and aren't about to stop now.

Edit: hiding content behind a click is indeed censorship, but it is not the only form of censorship on Hive. The Canadian Truckers that protested Canada's tyrannical government suffered the seizure of the bank accounts. Financial encomiums encourage content authors, and financial deprivation discourages them. Censorship is any suppression of speech, and flags certainly constitute censorship. It is flags that have driven off ~1m Hive users since 2016, silencing all those voices that were once here posting content.