I use a dt once a week. I just add oils and honey to gvpcb. If you have a conditioner you like that does not irritate you, you can just add oils and honey to it to make it more moisturizing.

As for curl keeper, it can give me stringy curls, but I scrunch out water with a microfiber towel before applying curl keeper, which keeps it from getting stringy.

I have found oils to be disastrous in my hair, unless they are added into some other product. They give me very stringy curls. How do you add them?
Also, oils do Weigh my hair down. I think this is because it traps the water underneath it, which in turn weighs down my hair, and makes it take even longer to dry.

You may want to try a mousse or a foam for styling. Mousses don't work for me, but the DevaCurl volumizing foam works really well. It does not weigh my hair down at all.

You could try skipping the oil, scrunching out water then adding a little bit of product. I think it is mostly about experimenting.

Also, since you have fine/medium hair, you could try a protein treatment. These perk up my curls and cut back on frizz, which allows me to use way less product.
3a/3b, Low porosity, Medium Density
Low-poo: Shea Moisture Moisture Retention
RO: Matrix Biolage Conditioning Balm
Leave-in: Kinky-Curly Knot Today
Styler: Aussie Instant Freeze or LALSG