I looked at the Custom GL Lines plugin and I don't think its the right tool for the job as its purpose is to add custom GL Lines when needed and has no effect on standard GL impact. We are currently leaning towards your idea, Matrim of using a custom record type with a script driven approval process.

I spoke to customer support about this. GL is always affected as soon as a bank deposit is created. The feature to pause the GL impact of a transaction until its been approved is not currently available as of release 2019.1. It may be added if enough customers want it! In the meantime there is a plugin that may help called…