I'm getting really tired of hearing how replaceable the safety position is. The best freaking player on the entire defense is a safety and he's all over the field on every play. I'd argue the 3rd best player on defense is also a safety, with only Mosley between them and a wait-and-see on Q.
It's not just about safety being replaceable. It's also about how the franchise tag is much more valuable for safeties (and tight ends)
If you franchise tagged Jamal in back to back years it would absolutely come out to less per year than he would get on a long term contract. While giving your team much more flexibility and control. I'm not suggesting you tag him back to back, but the money he will command on a long term deal is so much less attractive than utilizing the short term options available, BECAUSE he plays safety.
The highest paid safety currently gets 14 million a year. The franchise tag for safety is 11.5 million. Tagging back to back would be 13.8 million. Jamal would likely get more than Kevin Byard.
So yes extending him too soon is silly.