Well, in my previous post I wrote "it doesn’t matter which style of jhana or which level of jhana, as long as the mind can become steady, free from distractions and hindrances (including distractive thoughts), with which we can gain true knowledge [only a hindrance-free mind can see the truth)". After a second thought, I think the training methods do matter since some might not really lead to sufficient steadiness of the mind needed for gaining true knowledge.
"With his mind thus concentrated, purified, and bright, unblemished, free from defects, pliant, malleable, steady, and attained to imperturbability, the monk directs and inclines it to the knowledge of the ending of the mental assavas".
The jhana/vipassana combination method described in MN 111 might suit only those who have already mastered high level of samadhi and can enter/exit jhanas at ease. Ven. Sariputta was an ascetic for years before becoming the disciple of the Buddha, and was able to reach the 8 jhanas one after another and finally the cessation of perception and feeling within two weeks. Considering that even the Buddha needed one year to master the nothingless jhana and another year to master the neither percipient nor non-percipient jhana, very likely Ven. Sariputta had also mastered these two jhanas before coming to the Buddha, so he could proceed so rapidly and do vipassana while in jhana.
Just some food for thought.
Metta to all,