Ok so from what i understand there's this sort of balance between a virus transmisibility and it's lethality.
Since a natural virus that kills too fast won't spead that long besides being detectable, but one that's mild enough to spread a lot won't kill so many people in proportion.

So would it be theoretically possible to make a virus that's the worst both worlds?, something that's incredibly contagious but has like some sort of internal clock built by which it wont exhibit any symptoms at all before for a certain amount of time, like say years, and during that time its 10 times more infectious than corona, but once the timer its up it display the most horrific symptoms all at once. Would a bioweapon like this be possible? How about a nano weapon?