Thanks again Asad (sorry for the previous misspelling), but I actually got a fix from my colleage before I saw this (It may be the same as the last two in the link you gave:
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>> s = settings;s.matlab.desktop.DisplayScaleFactor
ans =
Setting 'matlab.desktop.DisplayScaleFactor' with properties:
ActiveValue: 1
TemporaryValue: <no value>
PersonalValue: 1
FactoryValue: 1
>> s.matlab.desktop.DisplayScaleFactor.PersonalValue = 1.6
s =
SettingsGroup with properties:
mldrivetripwireaccess: [1×1 SettingsGroup]
matlab: [1×1 SettingsGroup]
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This worked fine, and all within MATLAB; no mucking around with linux.