I'd certainly start out using the same keyboard settings as you have on your iPad since that works for you. What troubles did you have pairing to the iPad - and is it the same with the iPhone?
I had experienced issues sometimes pairing to my Mac in the past and it could take multiple attempts. There are various things that seemed to make it more likely to work. In my case, it was when trying to re-pair after having changed a jump slot to pair to something at the Apple store. Never had any trouble pairing to anything at the store. It only gave me trouble when I tried to get it back to my home system for some reason.
In any case, I would often try turning off BT on the Mac, erase the slot I'm trying to re-pair to by holding down the proper jump chord for about 10 seconds (the LED blinks faster and faster and then flashes when ready). About the time that flash happens, I turn on BT again.
There can be some confusion in what is on the screen - maybe the same happens with iPad and iPhone but I haven't tried repairing to those in ages. You can get more than one TextBlade item listed. I have found that usually the bottom one is the correct one to select (though I think once it was not). Then comes the important part - do you get a 6 digit pairing code. If I don't, I try again.
Sometimes I wonder if there is a problem with my Mac, since it never gave me a problem at the Apple store. In any case, eventually it always would pair. I have also noticed that if the TextBlade entry has a 4 digit hex code after it, it probably isn't going to give a pairing number. I think I had one exception to that. You will get the hex code added to it after you pair with the first digit being the jump slot number. But normally that hex code shouldn't appear before pairing.