Prognastat
Author-san I have a suggestion, when the Mc uses the Hogyoku to evolve you should give him an "ability" like "Devour" or "Super analysis (Daikenja)" from Tensura, like in that fic "That Time I Got Reincarnated In Bleach" , if the Mc is going to "clean" Hueco mundo he should get all the benefits he can (powers of the zanpakuto and racial abilities) and not just the EXP.
Note: his ability "Transcribe" can evolve to Devour because as you have said, transcribe cannot copy racial skills (such as poisonous spit because it does not have poisonous glands) and I suppose that by itself it will not be able to copy the zanpakuto either but with devour and analysis it would be possible .
I can see no benefit for him meeting hallibel. After all it won't be long for aizen to turn her in an arrancar and then he would have to let himself be turned too or leave, which would put him on aizens radar either way. His best course of action should be to become a vasto lorde and then plan from there.
He could try and kill them for exp but the leader would chase him to the ends of the world if he did. But how can he evolve more when someone is watching him or even worse when he is turned into a lackey with these 3. But serving one of the best potential love interest has it's perks. Thanks for the chapter.
The mc should focus on becoming a vasto lorde ASAP already if he is going to ve noticed by other soon to be arrancars, it's better to be in a position of power over them or on equal footing atleast.... That does seem to be his modus operandi till now... Hide-gain power-confront-gain power-hide-gain power 😅.... He should keep this up till we get more momentum on the wider spectrum of the bleach world... Nice interaction with the other hollows... Need to read more to say anything further! Thanks for the chapter.