They are doable but you should mitigate your risks as much as you can.
Scout the system and account for people. Having anyone warping to the FOB will draw a spawn. Watch local too.
Use a covert-ops ship and combat probe the FOB, you want to put a few bookmarks there. One or more beyond neut range (>275km) where you can deal with the FOB spawn before hitting the structure.
Put another at your optimal range.
Whatever ship you choose, have a mobile depot, mobile microjump unit, and drones to refit. Microjump unit is backup#1
I also recommend an alt in a throwaway “hero” ship that can warp to the FOB if you need to evac. It should have at least one offensive module +drones. This is your backup#2.
Most people use the passive Rattlesnake it seems. I have done both faction FOBs sniping with a Golem at 280km. Takes longer, but I have less issue with the response fleet that spawns from the Hauler at the FOB. I can ignore the ECM from the Guristas, thx bastion. If I get the multiple Osprey spawn I usually warp out and wait for a better spawn the next attempt.