Of course SDI and VPDI are different.

However, the total amount one pays into California disability insurance (whether SDI or VPDI) is still limited to the annual SDI limit.  With 2 or more jobs, the limit is frequently exceeded.  When this happens, the excess paid into all CA disability insurance plans is credited on Line 74, just like excess SS from multiple jobs is credited on Federal.

Here are the instructions from FTB on Line 74:  

Line 74 – Excess California SDI (or VPDI) Withheld

You may claim a credit for excess State Disability Insurance (SDI) or Voluntary Plan Disability Insurance (VPDI) if you meet all of the following conditions:

• You had two or more California employers during 2019.
• You received more than $118,371 in gross wages from California sources.
• The amounts of SDI (or VPDI) withheld appear on your Form(s) W-2. Be sure to attach your Form(s) W-2 to the lower front of your Form 540.

They key here is whether Lacerte is properly calculating this excess.  With 2 taxpayers so far, I have found that it wasn't without my workaround.  The fact that the workaround "works" tells me that Lacerte knows about excess SDI + VPDI, but has a bug somewhere.