I did about >400 epidurals, >400 MBBs, >150 RFAs, a ton of TPIs, peripheral joint injections, and ultrasound-guided stuff (including peripheral nerve blocks and peripheral RFs), and about 15-20 each of SCS and intrathecal pumps (trials and implants) during fellowship. No Vertiflex (or any other interspinous process devices--no insurance coverage), no kyphoplasty (surgeons did them at our institution), no MILD (no insurance coverage). We had 5 fellows and each fellow did procedures 1 day/week.
Also, don't forget to focus on the actual diagnosis of pain. I live in a city that is chock full of interventional pain physicians, and few listen to or examine a patient. Almost every new patient I see has seen a few other pain physicians, and 'nothing has ever worked' (also, I rarely prescribe opioids, so they're not coming to me for those).
You can do all the epidurals, MBBs, and RFAs you want, and none will matter if you're not treating the source of the patient's pain. IMO, the most annoying and lazy diagnosis I see is "non-specific low back pain" and treatment is "two/three level bilateral TESI x 3". Learn how to master diagnosis (and how to communicate effectively with patients) in fellowship. Do as many procedures as you can, and learn how to manage patient calls and post-procedure 'issues' (be they real or imaginary) during fellowship.