I'm obsessed with Shirahama's lore drop about Qifrey learning swordsmanship skills during a period of traveling alone. I'm thinking that Qifrey's adventures without Olruggio inflicted deep emotional damage on both of them from being apart. Swordsmanship training probably took quite a bit of time, so maybe, MAYBE, Qifrey and Olruggio reunited with much longer hair?!?!
I can totally imagine Olruggio letting himself go when Qifrey, the person that takes care of him during his contraption-inventing cycles and the person he would clean up his appearance for, sets off on dangerous adventures without him (and explicitly did not want Olly to come along, or else Olly would've scoured the ends of the peninsula to find him just like in the light novel). Then, when Qifrey felt ready to reunite with Olly (perhaps after coming up with the idea of having apprentices to add to his worries and make it possible for him to live with the man he loves), he returned unannounced to a miserable, disheveled Olly.
Of course, Qifrey bummed it out during his sword training arc as well. But maybe Qifrey would make himself a little more presentable before finding Olly in the Great Hall (or not, because he wants to see his dear friend as soon as possible, and shows up super disheveled too!!) Ugh, I think Olly would just about collapse when he gets to reunite with Qifrey.
This places Qifrey's solo adventures sometime after the fourth test (he probably would've been an independent witch for these adventures), but before he decides to take the fifth. Then comes the events of the light novel, where people tried to suggest to Olly that Qifrey's disappearance from the Great Hall could be in preparation for the fifth test. It puts Olly's frantic search for Qifrey in the light novel into perspective!!!
Honestly, it's so funny in the current canon when we see Olly living out the cutest, slice-of-life, shoujo story while Qifrey drowns in The Horrors. But I can totally see this being the result of Qifrey putting Olly through the emotional WRINGER during their time apart, and Olly just being so happy and thankful that Qifrey has finally settled down by his side (which adds another layer of depth to Olly's concerns about Qifrey's self-destructive, avoidant past when Coco comes along). Plus, I'm sure Olly loves living under the open sky as much as Qifrey does, so from his perspective, life at the atelier with his most cherished friend is a dream come true.
Anyways, if you're also excited about this missing time period, I've been absolutely loving this fic of Qifrey and Olly's letters during their time apart by @calamity-unlocked!!! It's just SUBLIME!!!! https://archiveofourown.org/works/86547061/chapters/229007561 Edit: Wait wait, there's this fic that begins with their reunion by @pazories!!! LOVE LOVE! Very excited to see what happens!!! https://archiveofourown.org/works/87251651