scything rolling crimping and the dreaded tilling under

I've got a small backyard plot where I intend to grow vegetables next season. Beforehand, I'm trying my first hand at cover crops. I'm doing oats, hairy vetch and field peas, sold as a "green manure" mix for tilling into the soil..
I want to leave it on top as mulch and I'm debating crimping or scything..
Similar topics been discussed but my question is specifically, (aside from how much the soil strata are affected) Will the oats\vetch\field peas come back if they're cut at the root, just below the soil surface?
I've seen excellent info/ videos of cover cropping on a large scale, but here I've got reasonably loose soil, a small plot, and these cool serrated hand blades they sell here in Japan.
I've read cooperative extension reports that some 20-odd % of vetch survives crimping (don't quote me on the number).
I'd appreciate any info.
R

They don't come back if they are in the seed forming stage, usually... For oats that is when they get the first tinges of brown or just past the milk stage (the oats have filled and just starting to thicken/harden). Wait too long and the seed will be viable. Not sure on the vetch or pea

The problem with crimping is (at least on a large scale) that you have about a week window of time that will kill without viable seed (or less) but your plants across the field have a +/- 2 week variance in maturity due to seed variation, microclimate and soil conditions.

Small scale, I would use the hand scythe (what is the right name for those cool Japanese versions?) and simply re-do it for those that didn't kill--that is just more biomass without paying for seed.

Thanks for the info..
That's what I think I'll do this time around at least..

The sythe/sickles (I suppose I should get my English straight before I refer to things in Japanese) that I mentioned are called,
"nokogiri gama" (saw sickle)...　　In Japanese characters it's: 鋸鎌　or のこぎりがま.