If you are already accepting disappearing and reappearing characters with no explanation, and are trying to bend the game into getting to use your best stats for every roll, you might as well just ask the DM to handwave the secret doors. “Uh…I guess Bob the Rogue magically popped in long enough to point out that secret door before vanishing again…”
Seriously, enjoy the fact your characters have weaknesses. Use that fact to create interesting side quests. Find another way around the secret doors. Go sweet talk a wizard into lending you a Wand of Secret Door Detection (and what storylines might pop up from that?). Turn the challenge into a cool story to tell.
And if you’re stuck in a dungeon, can’t leave, and are totally dependent on finding secret doors to progress….well, that’s a bad dungeon. And if such a thing is common in your campaign, maybe your group should have built some redundancy into your characters.