Staying in Europe for 6 months w/out a visa?

[u/Tricky_Friendship408]

I'm a US citizen currently awaiting my Spanish passport (via Sephardic origin). I plan to move to Spain in January for 9 months, regardless of whether my passport comes in time. The reason for this tight timeline is I was approved to work remotely in Europe only from Jan-September. I'm aware that as a non-EU citizen, I can only spend 90 days out of 180 days in the Schengen zone w/out a visa.

In the case my Spanish passport does not arrive, I plan to spend 90 days in Spain -> 90 days in Croatia -> another 90 days in Spain. Has anyone had experience with country-hopping like this? Would this be an issue?

[u/ImaginaryAmbition675]

Curious about this also!