I really dont see where the issue is, this is the way we have adapted::

(1) I keep a cheap phone for voice calls (Zain postpaid) - and all piips I know are familiar with this line (though Safcom piips flash me a lot !! )

(2) I keep an iPhone (or any other high end device) on Orange data (or Yu);;

Cos the way Safcom charges for data is just too fishy;; With Orange and Yu, 2 soc lasts quite a while,and the bandwidths are good enough to read emails and refer to quick searches eg wikipedia and short Youtube videos

(3) I keep a Safaricom simcard in my wallet; for those few in a month occasions when I use Mpesa

I do not think I will benefit from Number Portability.

w/regards
Stephen N.