There's not a lot of organized teamwork on Battlefield 3, so it's hard to have a SOFLAM user assisting the Javelin launcher. Is it possible to spawn as the recon class, set your SOFLAM down, commit suicide, then spawn as an engineer with the Javelin equipped?
This is actually impossible. I've tried it earlier today, if you place a SOFLAM and commit suicide, re spawn as an engineer with a Javelin, the SOFLAM will be gone.
The only way to use SOFLAM and still take something down yourself is to use a Guided Shell for a tank or a helicopter. Even that is difficult, having to get out to laser tag (SOFLAM is meant to be autonomous but it's bugged to hell, doesn't tag things right in front of it sometimes) something then get back in, get a lock on and fire.
To sum up, no, you can't put a SOFLAM, suicide, and use a Javelin. It needs two people.
I see most of these comments were from earlier this month and I found some comments to be inconsistent with my own experience. Maybe a new patch changed things?
Anyways, my AT mines stay (longer than 20 seconds. I think they stay forever) because I would continue to get points after I die (and more than 20 seconds since). Same as my C4. I'd place my C4s and get killed, but then I'd respawn and detonate and still get kills. But I'm here for the same question. It would appear my SOFLAM disappears every time after I respawn as engineer, which is troubling.