Glad I could help. I’d probably avoid the open baffle tweeter, you are more likely to reach excursion issues and it can cause phase problems making your crossover design (active too) really difficult because you then need to measure the phase and offset it using FIRs. Probably worth just enclosing it since it’s unlikely to be worth the effort to do the phase correction for that.
In terms of ohms, you will be perfectly fine if the impedances are 8ohms. I assumed you had 4 ohm drivers (as I have). An amplifier can drive anything above its minimum, it’s just less efficient.