Thank you - what we're looking to do is dramatically simplify existing screens for accounting etc. and optimise it for mobile. Hence thinking that editing code (to remove functionality) would be more straightforward than building a new accounting module from scratch. Would welcome your views on whether there is an easier/better way for us to do this.

the issue with this approach is that, we cannot say that odoo source code will not change again, if you take odoo14 now and edit the source code, there will be new new code additions like bug fixing, security improvement coming in coming days, so it will mess up the things.

You can see the changes coming daily looking at here: https://github.com/odoo/odoo/commits/14.0. Even yesterday there are 5 commits to odoo14

Thank you - I'm thinking to acquire Odoo Studio for community and do it that way instead.

Odoo Studio is available only for Odoo Enterprise, not for the Community Edition.

I've found a third-party Studio for Community, so I'm thinking of using that. I'm trying out the Enterprise one on a trial basis first, to see if it will do what I want.