Where are these stories? I haven't come across one. You do you. I have not seen it work well out for those who make decisions based on fear. This process has lifetime implications. A VA rating can be corrected at anytime. If you sign off on something now the chances of getting it changed via an ABCMR in the future are near zero.
Also, if the Soldier wrote DOD Purposes only and the VA didn't adhere to it then it would be a pain but would get fixed and changed back. That's no different then the VA screwing up and ordering RFE for conditions that by their own regulations should not be reviewed. It can happen but its slim and fixable. Not so, once completed with IDES or LDES. Even if you love CHAMPVA and get it for your family you have no control over how it will be in the future. Programs can change for the worse. Tricare gives you options not possible with other health insurances. My wife is medically retired and on SSDI. She has access to Tricare, Medicare, & VA healthcare. She gets most of her medical from the VA but the VA won't cover the medication that her community health provider prescribes for one of her more severe health conditions. She is able to get the best treatment due to having more than one option. The medication that helps that the VA won't cover she gets through Tricare with no problems.
When making life altering decisions its best to look at the long game. I can't picture a scenario that is likely where not giving yourself the best shot at a medical retirement is