The thought of putting Dueland caps into CS2.4 is wild to me. Even if Dueland makes the proper capacitance values (I don’t see anything close at Parts Connexion), the price would staggering. Multiples of the original price of the full speaker. But I would love to hear the outcome!
I suggest taking Tom Thiel’s advice, go with Clarity Cap CSA. Ideally, get full capacitance in single caps. 14 and 28 uF are tough to find but I would avoid going with 13+1 and 27+1 as in the original CS2.4. Running caps in parallel, I would go with something like 10+3.9+0.1 and 18+10. Try to get a more even balance among the two bigger paralleled caps. The 0.1 uF bypass is where you might go crazy and install a super-ultra bypass like a Dueland or Jupiter (even those are expensive!). You could add a 0.1 bypass to the 28 uF position as well.
Tom pointed out that the higher voltage models (eg, 630 V) have thicker film which is desirable, especially in the coax feeds. But I heard a difference even in the woofer shunts with 250 V version sounding more impactful than 100 V version of an otherwise identical cap. If your budget extends to Dueland$, definitely you can afford to replace the electrolytics in the coax shunts to film caps. Clarity Cap is a great choice for these, although be warned that their size is far greater than the electrolytics. That is, you might be challenge to fit everything within the passive radiator chamber.
Definitely upgrade the sandcast resistors to Mills MRAs or, if your pockets are Dueland-deep, maybe try Path or Dueland graphite resistors. Again, those ultra re$i$tors are hard to find in the proper values for the CS2.4.