Provide special versions of the (glulx) interpreters that could help isolate performance problems, etc. I know that David Kinder has made special versions of interpreters to test, say, the time required to draw individual images; with some work and forethought, this kind of thing could potentially be expanded (hopefully in an accessible way) to allow folks to run down issues that otherwise can be difficult to isolate. The Mac version of the IDE currently has a natural UI to choose between alternative interpreters in the preference menu option to choose between glulxe and git, so the major issue with this would be developing suitable interpreter(s).

The linking verb "is" is magical. But sometimes you'd like the verb "has" to be magical too.

Definition: a person has arrived if ...
Definition: a person has expired rather than survived if ...

In some cases you can naturally substitute an "is" form ("a person is dead if...") but not all. "Steve is arrived" awkward -- in my country -- and "Steve is here" is liable to run into parsing issues.

In general, this comes up because IF state flags frequently refer to past events (even though the game code is really testing their present values). It's nice to be able to name them that way.

Other cases:

[Binary properties: (A goal is a kind of thing.)]
A goal can have succeeded.
A goal can have succeeded or failed.

(Goal-1 has succeeded; if goal-1 has succeeded...; if goal-2 has not [or "hasn't"] succeeded; a random goal that has succeeded; the number of failed goals; etc.)
I'm a little unsure about using the term as an adjective -- an arrived person, a succeeded goal -- but it's not too ugly.

[Multi-value properties:]
A person can have fallen, jumped, or been pushed.

[Relation prepositions:]
The verb to have fallen for implies the crushing-on relation.

[Relation verbs:]
The verb to tip off (he tips off, they tip off, he tipped off, it has tipped off, he has been tipping off) implies the snitching relation.
[Or wait. Do I mean:]
The verb to tip off (he has tipped off, they have tipped off, he had tipped off, he was tipped off, he was tipping off) implies the snitching relation.
[Or is this road paved with pluperfects? Maybe we should skip relations.]

[Property verbs:]
The verb to have weighed (it has weighed, they have weighed, it has been weighing) implies the historic weight property.
(This compiles, actually, but then you can't use it. I suspect this gets tangled up with the past-history mechanism, as did the relation verb example. Oh well.)

Better and more syntax to refer to kinds, and variables that
range over kinds. Some proposed syntax:

The current monster class is a kind that varies.

now the current monster class is the kind of the attacker;
now the current monster class is a random kind of monster;
if the current monster class is a kind of monster: ...
if the current monster class is a direct kind of monster: ...
repeat with current monster class running through kinds of monster: ...
now the second monster class is the parent kind of the current monster class;

This would allow us to determine whether two objects have the same kind, to
traverse at least the object branch of the kinds tree, and so on.

I had the phrase: To decide which object is named-1 (name - some indexed text)...
And it was quite a while before I realised that I had to invoke it like "let x be named-1 (text)", and not "let x be the

object named-1 (text)".I think the second way is more natural, as the first might be misunderstood as a change to x's name.
Diving into documentations, I figured that nobody expected phrases that have arguments/return values and are better named

as adjectives."11.16. New conditions, new adjectives" and "13.12. Relations which express conditions"have a similar ring,

but nothing I found could allow the syntax I had in mind while supporting complicated operations(searching for a best

match, in my case).
I feel that such a new syntax of phrases/adjectives/relations as conditions not only bridges the unnatural gap between

relations as conditions and phrase adjectives(which are logically the same thing, I suppose), but also expand the

philosophy of relations/adjectives--it will be possible to naturally ask whether a thing(or what thing) is beautiful for a

certain person. So, these I dare to suggest: if it's impratical to truly unite the two, or to distinguish between syntax of

adjective- and noun-named phrases (eg. which object is the subject of...), or to word the standard rules so that it doesn't

clash with user wordings like "named" (uh),then, at least it doesn't hurt to allow adding words like "the [return type]"

and "the [return type]that/which is" before the name of a phrase, does it?