Hi ian-birchall-ntl Thanks for reaching out to us here on the Community. The font size has a maximum of 12pt, the settings are located by selecting the cog/gear icon > custom form styles > edit, on the relevant template > Design > Select a different font > select the relevant font size > done. You could also try zooming in/out by selecting Ctrl + or - on your keyboard and there should be the zoom option within your browser menu.
I have submitted your comments/feedback to our developers and hopefully in the future they may be able to implement a more robust template function to include larger font sizes. I have included a link that you could use if you would also like to submit some feedback: https://intuit.me/3VYQIEt
