With any air kit, regardless of how low it’s designed to go, the rear bump stops have to be trimmed so that the bags will fit, that one is unavoidable.
The front wing seam might need a trim, but nothing major.
At the rear, it’s usual to cut a notch for the rear shock and brake line so the van isn’t sat on them when aired out.
That all sounds scary, but it isn’t really once you see it. All cutting is done with care and finished properly to ensure no corrosion issues arise.
It’s easy to think that huge lumps of structurally integral parts are being ripped out and thrown in the skip, but for a normal install that isn’t the reality at all.
Sub frame raise etc is not necessary, unless you want to get the last little bit of drop when aired out.
The inner front wing area can be left alone unless you’re trying to air out as low as possible.
I won’t be offering sub frame raises, or any of the other more extreme mods.
Cheers.