when using long patterns and utilising shift/space to play back from current position it only plays back samples that start on or after the current position -
would it be possible to playback all samples from their current position? as going back to the start of a long pattern to hear edits made near the end each time really slows down the ‘flow’ as it were.
The only way to play back samples from a position is using the 09xx effect command where xx is a position in the sample, this point is the size of the sample devided by 256.
This might change in the near future but currently using 9xx works best on short samples. The longer they get the less accurate you can make the sample play from a certain desired position and the less usable the 9xx command becomes.
(solution to this problem is cutting up the sample in smaller pieces, seek the renoise beatslicer tutorial on youtube.)
oh i know about the 09xx but i play a lot of guitar over very long patterns and then mess with the drums afterwards and its really awkward to have to use the sample offset on the guitar samples just to be able to hear it without playing all the way from the begining, oh well 
You do live recording on the guitar?
Okay… i was busy with an advanced video about Renoise and Reaper and synchronising it.
In that manner you can then use Renoise to perform the sequenced stuff and use the recording option in Reaper to time it then you can play your whole concept from any arbritrary position from within Reaper.
Meanwhile, I got some explanation and pictures that already can help you out further down in the thread here:
https://forum.renoise.com/t/syncing-renoise-to-reaper-or-other-sequencers/20784
Maybe this can help you out making it a bit less ackward for the time being that Renoise has no native sample synchronisation routines.
Btw the newest version supports MIDI slave mode which makes it a lot less ackward and control Reaper from Renoise.
ok thanks - i might try out reaper for this- but…any chance of full rewire support in the next update?!!
This is on the to-do list as well, and actually only a matter of when.
These are guaranteed as publically stated by Taktik himself:
1.9.1 → merely bugfixes and Linux support (and a nice surprise ofcourse!)
2.0 → AU support, lots of other surprises
Rewire may be somewhere in the midst of the 2.x series but no guarantees given.