[Therion] Minimum symbol scale

[Tarquin Wilton-Jones]

Hi folks,

There is a setting:
min-symbol-scale M

That allows you to hide all symbols of S or XS scale. That's useful when
you want to show only the most important symbols in a low resolution survey.

But is there a way to control this differently only for certain symbols?
Eg. I want to be able to hide all "point label" symbols of scale M-XS
but I don't want all my cave walls or breakdown choke symbols to
disappear (which are at the default M scale).

Essentially I want something like this:

min-symbol-scale point label L
min-symbol-scale point anchor:foo M

Some of this I can of course do with MetaPost. But labels (the thing I
care most about) don't allow you to easily redefine the MetaPost macro
... or at least the syntax is so weird that I don't understand it.

Thanks for any advice.

Tarquin