NotoSerifKhmer variable font (NotoSerifKhmer-VF.ttf) has slightly different advance widths than that of NotoSerifKhmer phase III static font (NotoSerifKhmer-VF.ttf)

[hrhatada]

STEPS TO REPRODUCE

1. On the device A, replace the NotoSansKhmer-Regular.ttf & NotoSansKhmer-Bold.ttf to NotoSerifKhmer-Regular.ttf & NotoSerifKhmer-Bold.ttf and modify the fonts.xml file
2. On the device B, replace the NotoSansKhmer-Regular.ttf & NotoSansKhmer-Bold.ttf to NotoSansKhmer-VF.ttf and modify the fonts.xml file
3. Reboot both devices
4. Launch Gmail, create a new mail and copy & pest the following text: "នៅ​ពេល​ដែល​មុខងារ​នេះ​បើក អ្នក​អាច​បញ្ជូន​មាតិកា​កម្មវិធី​ទៅ​ឧបករណ៍​ដែល​អាច​ប្រើ NFC ផ្សេង​ទៀត​ដោយ​ដាក់​ឧបករណ៍​ផ្ទប់​គ្នា។ ឧទាហរណ៍៖ អ្នក​អាច​បញ្ជូន​គេហទំព័រ, វីដេអូ YouTube, ទំនាក់ទំនង និង​មាតិកា​ជា​ច្រើន​ទៀត។"
5. Compare the compose e-mail UI on the both devices

RESULT : The compose e-mail body on the variable font device has more chars in the line than the static devices' UI

[simoncozens]

I don't see an obvious resolution here; at this point, we've been using the variable fonts for so long now that its advance widths are the "new normal".