I was going to mention Saalberg's outings over 800m this year, but Awsi Dooger beat me to it. Purely based off their PBs and training together, if Saalberg can run a 2:03 then Bol is already sub 2:00.
I don't think there is any doubt in Bol's ability & potential in the longer distances (600, 800). Her coach has seen this, as have others close to the group (notably, 1992 Olympic 800m Champion Ellen van Langen, who's now the meet director of the FBK Games). The problem is Bol doesn't currently want to run 800m, and they also heavily rely on her in the 4x4 relays, so focus on the 400m distance is paramount.
There are some theoretical possibilities though. Already this season Meuwly has been 'experimenting' with some of his athletes: we've mentioned Saalberg's outings over 600 & 800, but he has also moved youngster Britt de Blaauw back down to 100/200, with a view to concentrating on the 200m at the European Under 23s, and a place in the 4x1 team in Tokyo (she ran the last leg on the 4x1 at the World Relays). In 2026 there are no global championships; I tweeted to Meuwly it would be a good opportunity for Klaver to have a season of 100/200 to see what she could do (current PBs 11.33/ 22.46) and he simply replied with a 'like'. But I could envisage some experimenting going on next year, for Bol as well. Either more 400m flats....or an 800m.
Back to her opener in Rabat. All trolling aside, the facts are the facts: her fastest opener by 0.61. Also, intriguingly, over the last 3 seasons the difference between her 400m opener and her SB has been 1.77 (24) 1.67 (23) 1.67 (22) (that is discounting her near-altitude 50.95 from last season and using the 51.30 instead). If she has the same improvement, then in takes her down to between 50.60 - 50.79 at sea level.
Theoretical, but based off real statistics. Regardless of SML and her out-of-his-world WR, this is still absolutely amazing in it's own right and highlights SML would need to be at her best when they race in Tokyo.