SVG FF text sizing

by hhcofcmds

HTML

<svg style="width: 400px; height: 200px" viewbox="0,0,40,20">
    <text style="font: 1px serif" x="0" y="1" stroke="none" fill="black">ABC123 (1px)</text>
    <text style="font: 0.9px serif" x="0" y="2" stroke="none" fill="black">ABC123 (0.9px)</text>
    <text style="font: 0.8px serif" x="0" y="3" stroke="none" fill="black">ABC123 (0.8px)</text>
    <text style="font: 0.7px serif" x="0" y="4" stroke="none" fill="black">ABC123 (0.7px)</text>
    <text style="font: 0.6px serif" x="0" y="5" stroke="none" fill="black">ABC123 (0.6px)</text>
    
    <text style="font: 1px sans-serif" x="10" y="1" stroke="none" fill="black">ABC123 (1px)</text>
    <text style="font: 0.9px sans-serif" x="10" y="2" stroke="none" fill="black">ABC123 (0.9px)</text>
    <text style="font: 0.8px sans-serif" x="10" y="3" stroke="none" fill="black">ABC123 (0.8px)</text>
    <text style="font: 0.7px sans-serif" x="10" y="4" stroke="none" fill="black">ABC123 (0.7px)</text>
    <text style="font: 0.6px sans-serif" x="10" y="5" stroke="none" fill="black">ABC123 (0.6px)</text>
</svg>
<svg style="width: 400px; height: 200px" viewbox="0,0,80,40">
    <text style="font: 2px serif" x="0" y="2" stroke="none" fill="black">ABC123 (2px)</text>
    <text style="font: 1.8px serif" x="0" y="4" stroke="none" fill="black">ABC123 (1.8px)</text>
    <text style="font: 1.6px serif" x="0" y="6" stroke="none" fill="black">ABC123 (1.6px)</text>
    <text style="font: 1.4px serif" x="0" y="8" stroke="none" fill="black">ABC123 (1.4px)</text>
    <text style="font: 1.2px serif" x="0" y="10" stroke="none" fill="black">ABC123 (1.2px)</text>
    
    <text style="font: 2px sans-serif" x="20" y="2" stroke="none" fill="black">ABC123 (2px)</text>
    <text style="font: 1.8px sans-serif" x="20" y="4" stroke="none" fill="black">ABC123 (1.8px)</text>
    <text style="font: 1.6px sans-serif" x="20" y="6" stroke="none" fill="black">ABC123 (1.6px)</text>
    <text style="font: 1.4px sans-serif" x="20" y="8" stroke="none"...