(Disclaimer: This may be me not understanding how something works, and if so, I would appreciate it if anyone could explain!)
As the title states, loading any FX into an Sample FX chain, stops polyphony of that sample.
Any subsequent instances of a sample on a pattern stops the previous sample playing and start the new one.
It doesn’t really stop polyphony, but ends the ability of the intrument to be played spread over several tracks. I also wasn’t aware of that till yesterday. But actually the behavior is quite logical. The instrument wouldn’t be able to know, which part of the FX to send to which track. So the (whole instrument’s) audio signal is always sent to the last track the instrument has been played on. In the end native instruments using FX behave like a VST now.
Erm?
I can play sound from a single VSTi on more than one track at the same time. This functionality of not allowing an instrument to be played on more than one track when there are Sample FX involved, ruins my idea that I had to build a nice Synth interally in Renoise by drawing the waves to act as the oscillators, and pile on effects and routing within the Sampler.
If I don’t use Sample FX in the instruments, and instead use them on the track itself, it works, but I wanted to use this new Sample FX on the instrument to allow me to build a synth which can play its sound on any track, not just one.
Like a VSTi!
sure you can, but does it also allow to apply each track’s DSP chain to the notes that are played into?
if you achieved to do this, please tell me how you did, because Renoise shouldn’t be able to do it 
if you play a VST instrument in two tracks concurrently, and have not assigned a track to the instrument into its properties, the first track which plays the instrument (or, if the two notes start playing at the same time, the leftmost track) will actually play the notes, regardless of where they are visually put
OK, well I am going to refer back to my disclaimer; I was not aware of this functionality with VSTis. Thanks for explaining it.
I suppose it makes sense, and doesn’t mean my mission to create synth inside Renoise is totally foiled.
I would have liked the FX Chains inside the sampler to work as the effects do inside any VSTi, and not be bound to the track note is played on though…
Maybe in a future release this restriction will be lifted… when computers are powerful enough? 
Is has nothing to do with how stronge computers are , it has everything to do with voice allocation and how the program executes these.
Normal behaviour