> No userland util currently issues WSDISPLAYIO_USEFONT.

I came to the same conclusion a while ago.  Here's a (slightly more
general than the other one) hack I wrote.  Usage is like

	wsusefont iso8x16 > /dev/ttyE3

As the comment says, it's public domain; feel free to rip it off for
any purpose you care to.

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/* This file is in the public domain. */

#include <stdio.h>
#include <errno.h>
#include <strings.h>
#include <sys/time.h>
#include <sys/ioctl.h>

extern const char *__progname;

#include <dev/wscons/wsconsio.h>

static const char *font = 0;

static void handleargs(int ac, char **av)
{
 int skip;
 int errs;

 skip = 0;
 errs = 0;
 for (ac--,av++;ac;ac--,av++)
  { if (skip > 0)
     { skip --;
       continue;
     }
    if (**av != '-')
     { if (! font)
	{ font = *av;
	}
       else
	{ fprintf(stderr,"%s: extra argument `%s'\n",__progname,*av);
	  errs ++;
	}
       continue;
     }
#if 0
    if (0)
     {
needarg:;
       fprintf(stderr,"%s: %s needs a following argument\n",__progname,*av);
       errs ++;
       continue;
     }
#define WANTARG() do { if (++skip >= ac) goto needarg; } while (0)
    if (!strcmp(*av,"-dev"))
     { WANTARG();
       cfdev = av[skip];
       continue;
     }
#undef WANTARG
#endif
    fprintf(stderr,"%s: unrecognized option `%s'\n",__progname,*av);
    errs ++;
  }
 if (! font)
  { fprintf(stderr,"%s: need a font name\n",__progname);
    errs ++;
  }
 if (errs)
  { exit(1);
  }
}

int main(int, char **);
int main(int ac, char **av)
{
 struct wsdisplay_usefontdata ufd;

 handleargs(ac,av);
  { /* why the hell is wsdisplay_usefontdata.name not const char *? */
    char *fnc;
    bcopy(&font,&fnc,sizeof(char *));
    ufd.name = fnc;
  }
 if (ioctl(1,WSDISPLAYIO_USEFONT,&ufd) < 0)
  { fprintf(stderr,"%s: WSDISPLAYIO_USEFONT: %s\n",__progname,strerror(errno));
    exit(1);
  }
 exit(0);
}