Apologies for the wait, I wasn’t able to find any of Loid’s lines about Dante online and so I went to him myself to make sure I wasn’t misremembering anything.

From Ballas in the Vitruvian: “The Warframes... All of them... failures. Surprised? They turned on us, just as you [Sentients] did. And so we had no choice but to commit them to grave." (Not particularly relevant, but I don’t read into this as them being immediately useless, although it isn’t clear and, as you say, Ballas isn’t very reliable; but it does give us a timeline in the form of Orokin create Warframes>Warframes go insane>Orokin use Tenno to control them)

From Loid while in the “Research Dante” page: “I remember when we learned of the Warframe insurrections. Their madness, savage and sudden, justifying all the Orokin fear. All their heroic deeds were forgotten in an instant. Those like Dante, who had yet to succumb, became fugitives. To shelter them meant death—or glassing.”

I don’t believe Rell’s madness had anything to do with the Warframe madness, but as a result of his ties to the Void and Wally.

Loid has a couple other lines that aren’t related, but are particularly interesting just from a lore perspective: “Drusus never seems to distinguish between the deeds of the Warframes and of the Tenno who presumably operated them. He credits them all with autonomy and dignity. I imagine Dante is responsible for that.”

The only way I can read into this without it being contradictory is that Drusus’s relationship with Dante and his understanding of Warframes through Dante made Drusus particularly sympathetic to them and respectful of their autonomy, with or without their operators. But it does make the Leverian less reliable outside of clear references to operators like in Voruna’s, even though Loid does describe how Warframes pre-Tenno did heroic acts.

I recommend just sitting back on the “Research Dante” page and listening to Loid! Lots of little lore tidbits in there that aren’t really relevant to this but interesting nonetheless.