I updated my product catalogue based on existing customers' feedback, research and constant optimization. This pre-order idea turned out to be a single the most beneficial idea for me. There are two reasons for that:
I am keeping close strings with current customers and it pays-off. Understanding their motivation is also very important for me to make my products better for them.
Next: I focused on building products and improving the LP. The current product line is enough for me to keep offering pre-order and I will think about expanding them after I ship current ones.