Changing offset will not help you, it will only make it even worse (actually, it shouldn't boot at all). Changing the delay/autobootfix may help, however it may not.
If someone with boot problems is interested to help, I may try some ideas in my
HBL-Emergency (please post in the linked topic your 3DS version and if you're a N3DS or O3DS user). I would need someone to test if some modifications in the source code improve (or decrease) the boot rate. I now know that CakeBrah uses the GFX and you need to proper initialize it first before running it, or the boot rate will be pretty bad, so maybe cleaning the GPU memory first or something in these lines may help (and I want to test).
I wanna try there since I actually known my code, however if I find something that works I could share the code with
@cpasjuste, since some ideas (like autobootfix) are taken from his code anyway.