TV Streamer 2 and Phone Clip+ are backwards compatible with all wireless ReSound HAs.
Both your old and any new HAs will benefit tremendously from being used with Phone Clip+
You have a very wise wife . I’m certain the Vidas when properly fitted by a pro will outperform your old HAs, but if they are worth the extra money only you can judge.
I think that MFi is much overrated. With an iPhone (without Phone Clip+) you still have to hold the phone near the mouth so that the called party is able to hear you. With the Phone Clip+ on your shirt, you can keep the phone in your pocket or bag as the Phone Clip+ contains a microphone. To hear the telephone ringing in your HAs, the Phone Clip+ just has to be within Bluetooth range. I use my ReSound HAs with an Android phone with the Smart app which serves as remote control. When at home, the Phone Clip+ lies on the living room table and picks up calls from both the PSTN phone (with Bluetooth) and the smartphone. I answer whichever phone is ringing by tapping the answer button on the Phone Clip+.