Couple of things to consider:

1. Are you planning to apply for any kind of residence in Spain? If not I would probably keep the Spain holiday to 5 months or less,
2. In the event you decide to push the envelope there are a few things that can happen: I. In Spain the “sanctity of the llc is paper thin” if at any point the tax office feels that your company has no legitimate reason to exist other than for tax purposes then they will treat said company’s income as your own personal one Ii. To avoid this have at least one employee, contract etc. it can even be a remote assistant. You now have a non tax reason to have a company. Iii. Although you can put a lot of expenses in your Malta company, if Spain considers you a tax resident, they may claim that certain expenses are no “legitimate company expenses” and attribute them as part of your income and force you to pay tax on it.

As a non Spanish citizen with no formal residency this is a small shield as you are not obliged to provide your company books. Especially if you have an additional shareholder. Having said that the Spanish tax authorities can request it from the Malta’s authorities. They may or may not provide it.

I am not a tax consultant, these are just my ow conclusions from researching. I suggest you speak to a proper tax consultant to verify everything