While technicaly you are right, i think you missed the spirit of what the doc was saying.
You may write it all in a single process, but you will always have duplicated code blocks, especialy if those 3 types of hardware (ff,ff with reset, comb) share assignements with the same condition.
Honnestly, i haven't realy think about it.
Not a constraining one, but more something like :
Do what ever you want with it, but if you find a bug, please tell me, and if you use it in a project which has a lot of money, please, share a bit with opensource guys, don't be too greedy ^^
Chisel, SpinalHDL, Clash, Migen, Amaranth aren't HLS
Most of the time, if you get some verilog out of those tools with mangled names, it can be because of bad coding practice.
Here is some examples about how to preserve good names for SpinalHDL : https://spinalhdl.github.io/SpinalDoc-RTD/master/SpinalHDL/S...