Misfire, but no DTC's?

[fixkick]

oops no xls.?
the maf is ok.
the short pendings list is only what the ECU thinks is important for P300.s.
that maf unplugged test seems to me the injectors are clogged,or fuel pressure low , only on full demand(flogged up hills or wot)
or main filter is dirty. does the filter look 20 years old. if yes probably is, just glance at it, and can tell.

yes the balance test needs and injector pulser tool, to it pulses it and not burn up the 10 ohm coil inside.
my guess is this balance test is a waste of time if all 4 are equally clogged, as yours seem.
the injectors have 10micro sized screens inside (4 times smaller than main filter) an only back flushing them can clean those out.
the CAT is not melted or vacuum will seem backwards as you gun the throttle. (act so odd you will not miss that once seen)

if fuel pressure is at spec, at the bog, the injectors are clogged i bet.
if the propane test shows power returns the injectors may be clogged. (2 man test , one on propane hose , inserted in to IAT sensor port, pulle.
vacuum leak would have to be massive.
good luck to you, any have great NEW YEAR.