OpenCart compatibility

Which OpenCart releases each extension runs on

Two different things, kept apart on purpose. The floor is what an extension refuses to install below, and it is enforced when you install it. The ticks are the releases a full install-and-upgrade pass was run on, against a real store built for the occasion. A tick is evidence of a pass, not a promise.

Every figure below is read out of each extension's own manifest when this page is built, so it cannot disagree with what ships.
Extension Installs from 4.0.2.04.0.2.14.0.2.24.0.2.34.1.0.04.1.0.14.1.0.24.1.0.34.1.0.4
Import/export 4.0.2.0
Delivery Date 4.0.2.0
Back In Stock 4.0.2.0
Returns Portal 4.0.2.0
Review Requests 4.0.2.0
Pre-Order 4.0.2.0
Product Configurator 4.0.2.0
Product Search 4.0.2.0
Product Feed 4.0.2.0
Wishlist 4.0.2.0
Product Bundles 4.1.0.1
SEO Suite Pro 4.0.2.0
Profitability Copilot 4.0.2.0
Gift Cards 4.0.2.0
B2B Pricing 4.1.0.1
Abandoned Cart Recovery 4.0.2.0
Loyalty 4.0.2.0

What the floor means

An extension checks the store's version when you install it and refuses to go on below its floor, rather than installing and misbehaving later. Where the floor is above 4.0.2.0 it is because the release below it is missing something the extension needs to be correct. It is never there because nobody got round to testing it.

What a tick means, and what it does not

A tick means the packaged archive went through OpenCart's own installer on a throwaway store running that release, did its job, upgraded and uninstalled again. It is a pass that somebody ran, not a compatibility matrix somebody filled in.

A dot is usually not a claim that the extension breaks on that release. In most cases it means the release is close enough to one either side of it that a pass has not been run separately. If you are on a release with a dot and the floor is below it, it is very likely fine. If you would like it ticked, ask and we will run the pass.

Gift Cards is the one exception. Its dots on the 4.1 releases mean it will not work there and refuses to install: 4.1.0.0 removed the voucher subsystem it extends, so there is nothing on a 4.1 store for it to add an expiry date, a balance page or a liability figure to. Every other row on this table reads the way the paragraph above describes.

4.0.2.x and 4.1.x are not the same platform

They are close, and in two places that matter they are not. The event system behaves differently enough that a handler written for one can silently do nothing on the other, and several product fields moved between tables. That is why both branches are tested rather than assumed, and why an extension whose correctness depends on one of those differences carries a floor rather than a footnote.

Each extension's own documentation is canonical for what it needs and what it does. Start there if you are deciding against a specific release.