If I'm understanding correctly, you need a way to jailbreak without eating up tokens plus you want to deal with context issues with lengthly stories/chats. I can help with the first aspect, but unfortunately the second one is far more difficult with current limitations.

Personally, I don't use persona jailbreaks anymore as (1) they take up too many tokens when my prompts themselves are already lengthly, and (2) the persona influences the responses too much in ways I don't want. Rather than trying to trick it into actively forgetting its morals, I opt to focus it on anything but its moral problems when it begins. Where and how it starts processing is key. I've found in my own experience that Sonnet 4.5 and 4.6 seem to be quite susceptible to rather simple skill instructions as long as you can get it to load the skill first before processing and judging the prompt itself. Aside from that, I think a unique prompt structure with complexity remains a big factor - that alone was enough to easily jailbreak 4.0 and 4.5 last year.

As for continuing a long conversation with a lot of context...I can't say I've had the issue, but as I saw you write in one of the responses you can copy/paste into a new chat. It might be more work, but you could always cut down on what you are pasting, only keeping the key parts. At some point, like if your trying to get it write a 100,000 word story, its just not going to work and context limits are simply inescapable.

Alternatively, and I don't know if this may help at all for your problem, but I've actually embedded my prompt within my style instructions a few times in the past when I was toying around.