There are actually advantages in running BOTH Lead and Lithium together. Each has its own advantages and if you combine them, you get the benefits of both.
Obviously if you are limited by space and/or weight, decisions have to be made what to do, but not everyone is. most of the recent sales of my device that allow Lead and Lithium to run combined have gone to either people off-grid (where lead can be far better in very old temps) or with boats (where weight can be a bonus!).
In my Motorhome I have Lead Carbon - estimated Charge Cycles in the thousands - and also Lithium. The Lead rarely gets used so will stay in a good shape for a long time, but it is still there (automatically) when I need it. The Lithium gets all the use and will cycle between 100% and 10%. At that use range, it should last the 10 years of the warranty period and will pay for itself easily.
You can extend the life of Lithium easily by restricting the level you charge to and discharge to (loads of Youtubers promote that idea). But .... in order to have access to the same capacity, you will have to get additional batteries of course. Do that and 1) wiped out your supposed savings by restricting the useage and 2) if restricted on space, where are these extra batteries gonna go exactly?
simple rule with Lithium .... Buy It. Use It.
By the time it has been all used up, you will either not own the van any more or will have replaced with new bigger and cheaper batteries anyway.
