I like your custom themes working on all transaction types. Don’t change it. What is really good about your abstract is that I can change one form and it works perfectly on all forms such as delivery notes, invoices, payslips etc. It really is brilliant. So don’t change that because it makes sense to have one template working across all transaction types and you only have to maintain one template.
I think the problem may be more that I understand HTML 5 and CSS far better than I understand HTML 4 and tables. Tables are very hard to get text to display where you want it to etc. I also don’t know anything about Liquid so I don’t know the syntax.
It’s just that I am not a programmer, so I can’t for the life of me work out how to get the five field names (invoice date, invoice due, invoice number, po number and quotes to display 3 down and next two in next vertical column down. The problem with 5 field names in one vertical column is the huge amount of vertical space wasted and it pushes the main table with the items much further down. It would be better to have client address on LHS, quote and PO numbers in middle towards rhs and invoice details on far right. I have moved my company address to the bottom as a single line on the footer.
Other people on other forums also seem to have issues working it out. But I think it’s getting that sort of thing to work in a table instead of using CSS and HTML 5. I would normally use float or something.
So please do keep the abstract as it works well, but maybe rewrite to completely remove the tables other than for the main table and use CSS and HTML 5. Tables is no longer a recommended way for HTML to position text which is why it’s not supported in HTML 5