Originally Posted by
N104UA
If you want to avoid UA taking your miles and canceling your account buy the refundable ticket on another airline that departs from the same terminal and don't attach any FF#. There are only a few UA stations where this wouldn't work as UA is the sole occupant and no airside connection to other terminals (EWR), although there are reports of getting through TSA in this event, it just depends on the agent.
I know of people who have bought the cheapest one way ticket they could find (even from different carrier as you note) leaving within the same'ish time period to get airside with an elderly parent. If they couldn't return it they simply ate it. But this would get them through TSA to the gate area. As you note some airports there are limited or no airside connections to other terminals so you have to take this into consideration but it is done.