Intensive air purging

[mark_l]

Hi!
A friend recommended the following procedure for air purging:
1.Suspension-upper position.
2. Stop motor.
3. Unscrew pressure release valve (PRV) on pressure regulator.
Up here everything is clear and familiar, but:
4.Start the engine [:0][?] .
5. Wait few minutes, turn wheels couple of times...
6.Screw the PRV when motor running.
My question is: are any damages or problems possible when motor running with PRV open?
The common sense says "no" because unscrewing PRV we simply connect the pump with LHM reservoir (as I know). [:I]
Will car sink after engine starting as per Para 4?
Any suggestions?
Thanks ahead. [:D]