Yes, lower levels of conditioning ingredients are needed in leave-on versus rinse-off. It’s up to you to experiment but say you use 1% Dimethicone in a rinse-off, you could probably get the same effect using 0.1% in a leave-on.
Leave-on conditioners also allow you to use water soluble ingredients that just get rinsed down the drain in a rinse-off product. So you can use Glycerin or Propylene Glycol for a humectant effect. Or you could use Dimethicone Copolyol which is water soluble.
The other main difference is the use and level of cationic surfactants. They are the main conditioner in rinse-offs. Unfortunately, they can be irritating when left on the skin too long. Cetrimonium Chloride actually has a safety limit of 0.25% in a leave-on product. But for leave-on you don’t need cationic surfactants.
pH should be around 4.5 - 5.0. Rinse off conditioners have a lower pH because you want the cationic surfactant to stick better. But with leave-on, this is less of an issue.