NO, it is not important...

What IS important is the correct stiffness and flex characteristics

Buying the recommended brand guarantees correct match, particularly, if you are having trouble sourcing stiffness and flex details about a particular mast.

Pugs

Racycoot,
I am very similar in my disloyalty to particular brands and tend to buy the best available at the time, so my quiver is very similar to yours. I was using a 400 normal diameter fibrespar mast to cover 5.3 and 4.7 until it cracked. I replaced it with an Arrows skinny 400 and have found it improved the feel of both my Arrows 5.3 and North 4.7. So as long as the curve and stiffness requirements match, you'll be fine.

Now there's a thorny subject! I'm a sail tart too and have researched this question loads on other forums and emails to some manufacturers. Consensus is hard to find. Prob impossible.

One conclusion I reached is that RDMs and SDMs are different even if the bend specs are the same so the first question is does that sail like RDMs? Many say Prydes in the past don't, but then others insist they do with the right mast.

The other conclusion I reached is that the BIG 3 manufacturers (Pryde, Gaastra, North) have idiosyncratic bend characteristics for sails and masts that almost dictate that you match rigs. Cos I like being a tart, I don't buy anything from these 3 anymore.

Most other sail manufacturers stick to a more regular bend so you can mix and match quite easily. But you still have to check your rig setups on an individual basis. The Powerex skinny bend (incl Ezzy) in particular seems to be 'standard' and works well with a range of sails.