I've never received a dependable blade from the SAF except for
the stiletto, which was issued when I got my beret. Those, however,
were individually numbered and stored in the armskote where they
stayed.
Personally, I left the jack knife and the bayonet in my cupboard
and carried a Victorinox and a Gerber Mark II as replacements
respectively. Occasionally, I carried a Gerber Cliplock as a boot
knife instead of the Mark II, and the Cliplock was a lot more
compact and light than a bayonet.
I've seen some guys use a kukhri, but as a replacement for the
parang instead of as a fighting knife. When you've got to chop
stuff down, it's very handy.