My favorite speaker would change size and stiffness as needed to stay right on the edge of, but not exceeding it's capability to stay together and not fold, maybe just a few hairs stiffer and a bit more bullet proof.
As amps got bigger, designers of the speakers had to 'adjust' design [to avoid the worst nightmare of trying to launch any type of speaker...it blows too easily. In the case of the first famous English guitar speaker, the "Radio speaker" [salvaged from radio], news got to Jim M and Celestion that this is a preferred guitar speaker, a stiffened cone and a bit more power handling...enter the first celestion. The closest thing I believe is the A Blue 15watts.
Old radio and organ speakers? I have the Tramp on an Alnico Hammond 12''
As soon as the watts or power handling is bumped up, the original design characteristics seem required to change suit too.
What blows speakers these days ~ is heat, I believe it's when the speaker is in a situation where it can't be heard, sounding like crap as it attempts to exceed it's limitations while not keeping up with the other speakers. THat's not a good situation for sound or speakers.
Generally speakers last very long when sounding good [within their optimal 'window' of volume/tone compromises].
I would guess it's around 8watts that I prefer hearing a 10'' or 12'' speaker cone transducing. Driving amazing amounts of power through say a 12'' speaker, the speaker might be even working really well but the air doesn't sound friendly when super-compressed, yes it can be extremely loud, enough to cut through an intense band mix, no guarantee the tone will be close to anything or that the highs will be sweet.
It's all personal preference and
hearing preservation.
So, IME, a lighweight-ish Alnico seems to have low listener fatigue, and a certain set of compromises [every speaker has 'em] to include a smooth type of compression.
Tramp is necessarily easy for speaker to handle, max watts can be known [and varied to taste] as less than say 13, and will never be exceeded, SE amps 'traditionally' were wired to efficient, low power speakers.
How low can the volume be set and have it sound like the great speaker it is [when the bass kicking in in and the eq/compression antics begin] is important in a living room situation, or even smaller venues.