[elthox]

i prefer my way to clear swt when region is different.

[Mwahab]

v850, flash with ur FA, vo fix, patch fsc, then region change if black screen happened, if u can't do it or u don't have the tools, ask someone to do it for u safer.

V850 CLEAR is not necessary
VO FIX is not necessary

If he used the correct salapa so that it accept the FA, alot of features needs to be coded manually for his new region, so thats why vo coding fix overcomes these issues. 
You can argue its useless for the v850, however for (Alpine, korean, Asian in general) i prefer to use V850, thats my way of doing it, because i remember i noticed some differences in the Adjust block of ASIAN units.