It's interesting, that we're getting down to the sizes of self-replicating RNA that realistically can form by a complete accident.
Getting this sequence by random chance out of a pile of nucleotides is a 1 in 2^90 chance. That's around 1.2*10^27 or just around 20000 moles! Not at all an impossible number.
2009 paper: Self-sustained replication of an RNA enzyme [0].
Amazing! The 2009 Lincoln & Joyce paper you cited catalyzes one bond per hour on average. (Doubling time = 1 hour, but only one bond between oligonucleotides needed to double.)
OP's Gianni et al 2026 paper connects 45 nucleotides, taking 72 days (1700 hours) to yield 0.2%.
The latter effort is like drawing the whole owl.
That is incredible patience. Without access to the full article, I read only the abstract. I wonder if they used simulations to narrow the candidates?