I have a few laptops connected via WiFi. For that reason, after the initial full backup, I don’t want to have full image backups running as presumably it takes the same amount of time as the initial backup which is currently over a day?
Is it fine to just leave it running daily incremental backups without ever running a full backup again? (or at least for 6 months or so).
With 1.4.x incremental image backups are always based on the last full backup (sometimes called differential), so they might get larger over time.
There is no limit on the number of incremental images without a full one.
With 2.0 there are incremental backups based on the last image backup and synthetic full backups, so this situation is much improved for your scenario.