What is the deal on this stuff? :-)

I just spent my first 2-day intensive indoctrination with this vinyl
product from hell, most of it standing on my head or an approximation
thereof, in an extensive renewal/refit evolution with the usual
interfering lines & wiring, blind voids, galled clamp studs, insanely
planned/located associated equipment, and the rest of the gyrations we
come to expect on something called "a yatch."

Now, we know we need a good reinforced product for below-waterline &
pressure uses, and we even know that most plastic hoses require mild
heating for insert fittings. But it has caused me some post-battle
queries:

1) How may anyone effect a voyage repair aboard a small craft at sea
with this stuff? I was able to employ a heat lamp & reflector
arrangement within the limits of the onboard inverter, but not a heat
gun and certainly not boiling water in the work situations presented.
And this was while alongside with dry hose - not while rolling in a
seaway & with some inevitable water dripping through it that'd foil
attempts to heat it evenly enough for goodf assembly.

2) Does this material become irreparable with age due to changes in
properties? An adjacecent and otherise intact 3/4" sea suction line
of same of similar material required removal/trimming/refitting to its
seacock. Attempting to soften the trimmed hose for reattachment only
caused it to shrink, leading to a long delay & circus of trips ashore
which ended in creating a rubber hose adaptor for it.

3) Is there some compelling reason why reinforced rubber hose with a
suitable polymer barrier - which requires no heating or dubbing around
& clamps better besides - isn't in general use?

4) Beyond the obvious end treatments, is there some method of making
larger sizes of this "interesting" but uncooperative & pricy product
more easily routed in tighter spaces/radii?

5) Is there some compelling reason why yacht waste piping doesn't more
commonly employ rigid sched 40 DWV? (yes we know about sweeps &
expansion joints) In the case of blackwater wouldn't it last far
longer & be more vapor-impermeable? (not to mention that you could
*work* on it, pitch it so it'd drain & clean it if/when needed) I'm
not seeing an advantage to a very pricy hose that has R/R issues,
offers no timesavings in fitup, seems dicey to have to deal with at sea
& often (I am told) lasts only 2-3 years.

What am I missing here? ;-)

Bonus Q for the jaded: is there a implicit, international agreement
among those plan & specify such things, that the macerator pump shall
be mysteriously concealed within an inaccesible void locatable by
occultic divination, x-ray services or systematic disassembly of the
head compartment & foreship?

- f.