Im locked in for a year of claude pro, I encountered the same issues as you a couple weeks ago, Id get like one solid plan done and really really hope it was a 1 shot because that was legit all i was gonna get out of it for those 5 hours, and it would be ~10% of weekly usage to really make me feel scared to hit send.

I got the 20$ gpt tier, and now i just use claude to craft MD plan docs instead, and then i hand them off to gpt 5.4 and it has been working great. can do about 4x as much work or so based on my feelings(not accurate). if i have just small simple stuff to do i might still fire those off with sonnet and that seems plenty viable, but as soon as its an opus tier task i swap to this workflow.

Little annoying as now im kinda trying to manage a .claude/ and an .opencode/ folder but i kinda just have the .opencode/ stuff reference the .claude/ stuff so its a little less bleh.

I've been keeping within my usage because ive been in a funk a bit, but when i was slightly more worried id sorta just juggle whether claude or gpt would handle writing some initial tests as it did seem to kinda be imbalanced otherwise. seems like gpt just spam resets weekly usage throughout the week anyway so its prolly nbd.