X-Forwarded-for with SSL Passthrough (no offloading on LTM)

Hello guys, Need some help.

It was confirmed we cannot use X-Forward-For for SSL pass-through VIPs, but If I add it, what will happen. is the VIP still works?? I mean if the traffic is not offloading on BIGIP, can it ignore optional XFF http profiles and continue to work as it works earlier??

By mistakenly today I have added XFF to one of our old VIP, which cause huge outage. Our backend (apache) was recieving invalid HTTP requests / invalid SSL handshakes and stalling as a result.

I'm little confused here as BIGIP cannot add/modify http headers, how can the backend servers get invalid SSL handshakes. anyone have any idea!!