Because the basic ArM5 only know few way to perform magic what also shows in the virtue and flaws I'm now wondering if Rotes from Hermetic Numerology are classified as formulaic magic?
I personal think that ritual and ceremonial magic can be ruled out. But despite that in the text there is many mention that it is similar to Spontaneous magic I can't bend my head around that spells that first have to invented in a lab would be impossible to be cast by someone with Difficult Spontaneous Magic.
Would there be some advantage in classifying them as something else rather than just letting them be their own thing? Are there some virtues or flaws that are applicable to formulaic spells only that you want to apply to rotes?
This is another weird "what is this for?" mechanic. I personally would run rotes as counting as formulaic in any way that would benefit the rote caster and as not formulaic in any way that would benefit the rote caster.
Otherwise the point is casting quiet/still non-fatiguing level spontaneous magic if you spend seasons ahead of time learning them like formulaic spells - and you can get a bonus to this if you make them not quiet/still of +4/+8 (which is divided by 2 to +2/+4)! At the low level you're likely to be casting these, it seems that with the exception of busted stuff like Demon's Eternal Oblivion, penetration isn't really going to be a concern - you'll want to be using much stronger formulaic magic that doesn't divide your casting total for spells that require penetration.
For an example of what I mean, I have a magus who has Hermetic Numerology. He also has a Necessary Condition on his magic that he cast using a drawn casting circle, as a result of his personality and trouble managing his difficult Turbulences during apprenticeship. So, he casts with a highly structured method. I worked with my SG and ruled that while this applies to all of his regular hermetic magic, it specifically does not apply to his rotes! On the other hand, he does have Special Circumstance (Casting circles) which gives him a bonus to his spells and if he takes the time to use a casting circle while casting a rote, this will count as a bonus.
I assume that a Rote is not a formulaic spell, but a Rote. It is expressly possible to Master Rotes (TMRE 93), but otherwise they aren't specifically "formulaic spells" for things that affect formulaic spells. They are, however, "spells" )pg. 92) and therefore affected by things that affect spells in general.