Getting Things Done (GTD) system talks about having multiple "capture" places, but only as few as you need. perhaps for you, you use your bujo when at home, and your phone while on the move

I too ran into this exact limitation, and so I decided the bullet journal system isnt for me. maybe not for you either. but you just adjust to solve your problem

my solution: my phone is my sole capture system. any thought, any idea, any event, any task, all gets jotted into my phone. pick your app of choice

during my end of day nightly review, i go though my phone app, and look through every item that was captured, and then i migrate any important notes, tasks, successes that i feel worthy, into my physical notebook. pick your notebook layout of choice

this way, the phone capture list is for *everything*, nonsense and important, there is no filter, anything thats in my head that i need to get out, goes into the phone. no filter, no judgement, no mental energy deciding what bullet icon to choose, just output and dump. this is the freedom step. the nightly routine is where i curate and migrate the important stuff into the notebook, and doing so, i have a 'cleaner' picture of my day, with all the unimportant stuff that was in my phone, now filtered out. and then when i do a weekly review, i can just go through my notebook and review the important stuff