I was approved for a 500 CL with fingerhut last week. It is absolutely an admittedly desperate move to maximize my CU since my only other revolving account is a CapOne secured card with a 300 CL and I don't have the funds to throw at increasing that CL or opening another secured card. I have a 576 CR according to Credit Karma.
The merchandise is overpriced. The selection is decidedly meh - took me hours to find something that fit my personal taste and was also practical. And they will rob you with shipping: $17.99 for standard shipping.However, Google search will generally reward you with a coupon code for around ten bucks off (order or shipping, depending on the moon, it seems. It's the same difference either way.)
That said, if you're going for straight up CU all of these factors kind of create a perfect storm in a way. You're relatively unlikely to get swept up in the "oooh shiny!" trap because of the selection/price/shipping cost trifecta. If you're really taking the lessons here to heart, you'll make a smallish (~$100) purchase and smartly pay it down in 2 or 3 payments (more than the minimum but not paying it off so they don't report that you're using it wisely and you're still giving them a little on interest on top of their inflated prices.) I hear they are also generous with CLIs, especially when following the guidelines I just mentioned (however, I am too new with my own account to confirm through experience.) But again, if you're going for straight up CU maximization, it might not be a bad way to go?
Honestly, though, looking at the cards you've got and their limits, I don't think you need to go the fingerhut route, especially if any of the TLs in your sig are newer. You seem pretty well on your way to rebuilding, and you've laid a decent foundation. As long as you're keeping the debt on your TLs in the 10%-30% region, I think you'll be okay maintaining/gardening what you've already got.
