According to my current plans, the Spanish Civil War will be shorter than IRL, but its end and the associated aftereffects will have more of a profound effect on Europe than it did IRL
I really do hope we don't get a Republican spain. Because I think it would be a missunderstanding of why the civil war took OTL curse. First off, to assume German help was vital to the nationalist effort would be a great mistake. The germans certainmly proved helpful but their involvement was only crucial in getting the african army to the mainland. The Nazi airlift is probably the most critical part of the whole german involvement.
You see Franco was rather incompetent to say the least and I frankly believed under more competent leadership, the nationalist could have achieved much faster succes. First off, the Republicans simply lacked any structured command and army leadership for the first and half years of the war. The Army had almost in it's entirety declared for the nationalists and what few loyal generals remained were quickly purged by the republican administration. The Nationalist on the other hand, had a professional and seasoned army with the army of Africa and the Legion which was very pretty well equiped and had quite competent leadership. In addition they had most regulars on their side, and the loyalty of a good chunk of the civil guard (only half joined the cause at first but throughout the war lots of republican guards defected). Meanwhile the republicans had a deeply unorganized mess of an army, poorly equiped and made mostly of volunteers. In addition the left was just more intrinsecaly divided than the right and was much less suited for a war. The Carlists and falangists at the outsed had thousands of fighters well organized into quite sizeable forces with their own officers which were quickly and effectively incorporated into the army even before Franco assumed full power.
In fact, Madrid stood by the skin of its teeth, the republican government abandoned the city. At the same time, the nationalists plans were discovered by some papers discovered in an italian volunteer's pocket. And I've read some books were it's stated that had Franco not ordered for the Alcazar of Toledo to be relieved, Madrid would have fallen. Franco overall, was regarded as a pretty poor commander for his whole career and when in charge of the infantry academy of Zaragoza it was known that military knowledge was relegated in favour of political education. And it is also well known that he deliveratly made the war longer in order to get an unconditional surrender from the republicans.
Though for all of this to happen I must recognize the airlift was crucial and the continued air support also provided quite a bit of help. But to that I have two counterarguments, first off, Italy could be convinced to provide a replacement airlift which would have been slower but still effective and that I see no reason for Von Letow to not at least provide some kind of support, specially if Franco isn't around. Let's not forget, Von Letow is a deep conservative and providing some support even if not at the Nazi level is good for his agenda. Effectively getting an ally in the form of Spain can be very useful against France if push ever comes to shove and Spain has a mineral he desperately needs, Wolframium, which I'm pretty sure the germans would require in this timeline because much of the early german rearmament was already going on before the Nazis.
I would keep ranting about the political instability and all the advantatges and disadvantatges each side had, but this is already pretty long so I'll leave it as is. I might be completely wrong and afterall it's your TL and I'm sure most of the things that happen you have dedicated many to hours to reserch and ponder. This is just my opinion and by no means it's a universal truth and you have every right to disagree with my take. All in all, cheers!