We used exclusively RH cutoff tools and extend nose collets on jobs below 5/16" diameter. I use .039 wide cutoff tools for 5/16" and smaller diameters, but I do not do my back chamfers with the cutoff tools. I'll use a back turn or groove tool for those.
I run a lot of short parts, so using wider tools adds up to a lot of wasted stock and more tool pressure on the part in the sub collet.
I used left hand cutoffs and .098 wide inserts above 1/2" diameter stock.