Although I don't expect a lot of design flair from an accounting package, it would be a big improvement to allow font choice on invoice templates (system fonts (Verdana, Arial, Times etc) would be good; Google fonts even better). Invoice design is still part of an organisation's branding and being stuck with your standard font is rather limiting. Also, in this age of spammers sending fake MYOB invoices, having more customised emails that mirror an organisation's branding will help visually separate a properly branded email and invoice from an off-the-shelf look.
"Font choice on invoices"