Not really recommended for modern cars with ecu and catalytic converters, I done before on myvi with no damage but the car was definitely not running at its best.

If old datsun sunny or first gen proton saga then by all means go for it

beginner start manual car, free gear only start engine
pro start manual car, taruh gear 1, press clutch, start engine, extra 0.5 sec at traffic light....if kenot control well, car will jerk to front, then, engine mati  malu depan amoi

if mau jahanam the car, start engine with gear engaged  tapi legendary datsun 120Y and proton iswara tarak hal, no issue 

I was sharing my experience and advice I have been given before. Perhaps I may have been misled.

Sure, my dials misbehaving and electrics not working properly were all placebo. That they worked fine after battery change also I dreamt up.

Also, if battery is totally flat how would the ecu be powered? Pluck electricity from the air?

Want to call ppl bongok also watch your own words first. I am willing to admit I may be mistaken but if someone breaks something on your advice will you refund them?

i tot so long u free gear, can crank start your manual car liou (except when battery mati lah, then, u need to tolak kerata  ) without tekan clutch?

if u crank start your car with gear engaged, the car will jerk to front, then, engine mati? Of course some car more forgiving, like iswara and datsun 120Y, so, long u quickly press clutch or add speed, engine won't mati oso.....

and, u tukar gear without press clutch, hamjadah, the sound of metal cranking each others