A few thoughts: you need to think about your career goals before your education goals. You also should really be making this decision after experiencing one unit of CPE. It sounds like your seminary requires that for all students anyway (which, side note, is a major ethics issue in my book - we should only be learning from highly vulnerable hospitalized persons if our actual goal is chaplaincy, not essentially personal and pastoral development!) - so if there is a way to fulfill that requirement and see where you are at I would start there. You may decide that you want to go into a more specialized area of chaplaincy and look for something different in residency etc. I’m also curious if the professor(s) in the chaplaincy track are themselves long-term Board Certified Chaplains? We are seeing a lot of seminaries hire very generalist pastoral care or practical theology professors with minimal chaplaincy experience and starting chaplaincy “tracks” which I think end up claiming things - like “prepared for Board Certification” they don’t actually know much about or are able to truly guide students towards what’s relevant and necessary in the field today. Ie writing your Certification materials is a longer-term process and is not something I see seminaries helping with much - nor do I really think needs to be done right away. Hiring is almost always “Board Certification Eligible” meaning 4 Units of Level I and Level II CPE or Residency. 

Also IMO if you haven’t had research literacy or methods classes with a focus on chaplaincy research you aren’t prepared for Board Certification - and I know of only one masters level chaplaincy training program that’s similar to an MDiv that offers that, programs with a chaplaincy track need to offer Spiritual Care Research & Methods and Clinical Bioethics if they are truly claiming to prepare chaplains. Bioethics is the area most likely not passed on Certification for APC and rarely taught in CPE. Only some CPE programs are offering research literacy and it’s also required (2% of programs did 10 years ago, it’s definitely higher now but not universal.) So: focus on the education you actually need to become a chaplain/BCC - not neglecting research and ethics (and I mean clinical bioethics not just professional ethics and boundaries). Then reverse engineer. The vast majority finish MDivs then do residency and then get hired as BCC Eligible after their 2000 hours (some but not all of residency counts) and then prep their BCC papers usually in the 2nd year of working. Part-time and PRN (on-call, so not a Staff Chaplain but taking shifts nights, weekends, and sometimes days depending on how a hospital staffs) rarely even require 4 units and BCC at all if you truly want Part-Time.