My lad is in the same position. I emailed the club and they suggested he could swap to the Flexi gold, but as he wouldn't be able to attend the 16 matches, he'd be stuck with it.
I've no problem with putting his seat on the exchange, which we've done this year when he's not been able to make games, so it's the 10 personal attendance rule that will be the issue.
I did try downloading his ticket to my phone recently but it won't let me. Presume it can only be in one wallet at a time, so for next season may try and get his ticket onto mine and then I can use it occasionally if it hasn't sold to make sure we make the 10 minimum.
At the other end of the spectrum, my dad is in his 80s, does ok with his phone but hasn't worked out how to do the exchange and although he's linked and I can buy tickets for him, I can't put them on the exchange. He'll occasionally miss a game due to health or if the weather is really bad, so doubt he'll make 16 games so chances are next season will be his last.
Weird that City don't want older fans who've been going since the 50s to attend, or younger fans who are just about to start having disposable income. Maybe I need to get them both half and half scarves so they can get in