The biggest reason to blast over a cruise of Human Chorionic Gonadotropin (HCG), in scally's eyes, is the stimulation at the pituitary is different and more efficient when T levels are lower. meaning there is less inhibitory effect from high T levels, and high estrogen,
So it can do a better job at stimulating the pituitary, getting it ready to receive GNRH, the hormone that basically turns into LH and FSH.
On top of this we want to FULLY stimulate the testes, and 500iu a week will not give you a 1k T level.
either way will work, but on heavier cycles, I think the blast is necessary, especially with tren and deca, cause thats where they shut you down the hardest, at the pituitary.
Just my 2 cents.