Increased oil consumption?

Sometimes it is the type of oil used such as synthetic or conventional, oil weight matters as well, can i ask what kind and weight oil you used? Also, do you see any oil on the ground, it can be the oil filter or drain plug seal is the issue, please go over this guide to help:

https://www.2carpros.com/articles/engine-is-leaking-oil

Please go over this guide and get back to us, upload pictures or videos in your response.

The oil that went in was Castrol Edge 5W30 Full Synthetic, as prescribed by Mazda for the L-series engines.

There is no oil on the ground whatsoever and no leaks visible on the block or under the vehicle.

My first thought was that the PCV valve was playing up, but then I read that the piston rings on these blocks are a known issue.

Just the other day I increased the thickness of the oil, as I thought that the weight was the problem, so for a day or 2, it's running 5W40 full synthetic, but alas, issue persists.

Any other ideas or should I be looking to get the motor rebuilt?

It sounds like you have piston ring issues, you might want to check the PCV valve to see if the spring is broken.

Here is a guide I found that can help as well:

https://www.2carpros.com/articles/blue-smoke-from-engines-exhaust

I would remove the spark plugs to look for one wet with oil to help confirm the issue. Here is the location of the PCV valve so you can check it out. Check out the images (below). Let us know how it goes.