diff --git a/rhino/elemente.py b/rhino/elemente.py
index 63c2918..c57cb7d 100644
--- a/rhino/elemente.py
+++ b/rhino/elemente.py
@@ -440,37 +440,50 @@ def _list_hatch_patterns(doc):
     return out
 
 
+_RAUM_FONTS_CACHE = None  # einmal pro Session, danach gecacht (System-Fonts aendern sich nicht)
+
+
 def _list_system_fonts():
     """Sammelt installierte Font-Quartet-Namen via Rhino.DocObjects.Font.
-    Liefert sortierte Liste mit den haeufig benutzten DOSSIER-Fonts oben."""
-    out = []
+    Probiert mehrere API-Varianten (Rhino-Versionen unterscheiden sich)
+    und fuegt die DOSSIER-Default-Fonts oben an. Gecacht."""
+    global _RAUM_FONTS_CACHE
+    if _RAUM_FONTS_CACHE is not None:
+        return _RAUM_FONTS_CACHE
     preferred = ["DM Mono", "Krungthep", "Archivo Black", "Playfair Display",
                   "Helvetica", "Helvetica Neue", "Arial", "SF Pro Display",
                   "Times New Roman", "Courier New"]
+    raw = []
     try:
         from Rhino.DocObjects import Font as _Font
-        installed = _Font.InstalledFontsAsString()
-        # InstalledFontsAsString liefert ; oder \n separated — beide handeln
-        raw = []
-        if installed:
-            for sep in (";", "\n", "\r"):
-                if sep in installed:
-                    raw = [s.strip() for s in installed.split(sep) if s.strip()]
-                    break
-            if not raw: raw = [installed.strip()]
-        seen = set()
-        # Erst Preferred wenn installiert
-        for f in preferred:
-            if f in raw and f not in seen:
-                out.append(f); seen.add(f)
-        # Dann der Rest alphabetisch
-        for f in sorted(raw):
-            if f and f not in seen:
-                out.append(f); seen.add(f)
-    except Exception as ex:
-        print("[ELEMENTE] list_system_fonts:", ex)
-        # Fallback: nur die DOSSIER-Defaults
-        out = preferred[:]
+        # Variante A: InstalledFonts() liefert IEnumerable[Font]
+        try:
+            for f in _Font.InstalledFonts():
+                try:
+                    n = f.QuartetName
+                    if n: raw.append(n)
+                except Exception: pass
+        except Exception: pass
+        # Variante B: AvailableFontFaces (Rhino 7+)
+        if not raw:
+            try:
+                for f in _Font.AvailableFontFaces:
+                    try:
+                        n = getattr(f, "QuartetName", None) or getattr(f, "FamilyPlusFaceName", None)
+                        if n: raw.append(str(n))
+                    except Exception: pass
+            except Exception: pass
+    except Exception: pass
+    # Dedupe + sortieren, Preferred zuerst
+    out = []
+    seen = set()
+    for f in preferred:
+        if f and f not in seen:
+            out.append(f); seen.add(f)
+    for f in sorted(set(raw)):
+        if f and f not in seen:
+            out.append(f); seen.add(f)
+    _RAUM_FONTS_CACHE = out
     return out
 
 _TREPPE_SOLL_DEFAULT = {
@@ -10077,6 +10090,27 @@ class ElementeBridge(panel_base.BaseBridge):
             if not isinstance(r_layout, list): r_layout = []
             r_modus = p.get("txtModus", old_meta.get("raum_txt_modus", "fix"))
             if r_modus not in ("fix", "masstab"): r_modus = "fix"
+            # Modus-Wechsel: txt_h automatisch in die neue Einheit
+            # umrechnen, damit die Stempelgroesse visuell stabil bleibt.
+            # User hat 0.20m in fix → toggelt auf masstab → ohne Umrechnung
+            # wuerde das als 0.20mm@1:100 interpretiert = 0.02m Text. Mit
+            # Umrechnung: 0.20m @ 1:100 = 2mm Paper.
+            old_modus = old_meta.get("raum_txt_modus", "fix")
+            if r_modus != old_modus and "txtH" not in p:
+                try:
+                    import massstab as _ms
+                    scale = (_ms.get_applied_scale_ratio()
+                              or _ms.get_current_scale_ratio() or 100.0)
+                except Exception: scale = 100.0
+                if r_modus == "masstab" and old_modus == "fix":
+                    # m → paper-mm: paper_mm = m * 1000 / scale
+                    r_th = float(r_th) * 1000.0 / float(scale)
+                elif r_modus == "fix" and old_modus == "masstab":
+                    # paper-mm → m: m = paper_mm * scale / 1000
+                    r_th = float(r_th) * float(scale) / 1000.0
+                print("[ELEMENTE] Raum-Modus {} → {} @ 1:{:.0f}: "
+                      "txt_h umgerechnet auf {:.4f}".format(
+                      old_modus, r_modus, scale, r_th))
             gstart = p.get("geschoss", old_meta["geschoss"])
             attrs = axis_obj.Attributes
             if gstart != old_meta["geschoss"]: