Hi,
Given your experience, not sure/doubt this manual will bring anything new to your table, anyway 4.4.1 - 4.4.4, even if about thyristor and diode snubbers, and 5.9 - 5.? (I'm only at page 260...) about IGBT/MOSFET snubbers maybe could be of use/lead to an idea for what it is you're doing?
As you can guess, I know nothing about this area in practical terms, and very little theory either - I thought SCRs were happy dancing diodes, kicking a leg out, until a few days ago..., so will keep my mouth shut other than uploading the manual.