It's great Studio One has a low latency option, what would make it even more useful is if there were an additional option to bypass latency inducing plugins only when recording/monitoring. Logic has a similar feature, and it's one of the smarter and more unique things Logic brings to the table for MIDI composition, or overdubbing audio on a semi mixed session..
USE CASE:
The user has a session that is partially mixed, some of the plugins use add latency, perhaps one or two add a very large latency. The user needs to record additional MIDI (or audio overdubs), and in this case the latency either makes it impossible to record MIDI or overdub audio accurately.
The end result is TONS of undesirable editing after the fact, simply because the DAW isn't 'smart' enough to be able to disable latency inducing plugins only when recording.
SOLUTION:
An an option in the audio preferences, or or the transport that allows the user to enable the feature as needed. Ideally this option would be assignable to a shortcut, allowing the user to quickly enable/disable 'no latency' recording only as needed with a key command or button press....
IMPLEMENTATION:
Logic has a very clever way of handling this. The user can define a latency threshold (in milliseconds, samples, etc). If the user sets a threshold of 5ms, all plugins adding latency greater than 5ms will be disabled, only while recording or monitoring. The threshold time would ideally go down to at least 1ms, allowing the user to define how accurate they need their "no" latency recording to be.
When active, every plugin in a session that adds latency greater than the threshold would be bypassed, only when recording/monitoring.
In Logic sends temporarily bypass, meaning that send latency might need to also be taken into account...
This could also potentially reduce CPU load if implemented intelligently. For anyone working with large templates, MIDI, or vocalists, latency is kind of a big deal when re-recording instruments/audio in a semi-mixed session... If a session is somewhat heavily mixed already this can add additional problems such as dropouts, clicks, etc... Live input-enabled tracks combined with plugin processing are often one of the biggest single core CPU killers... Basically this would potentially solve multiple problems in addition to simply making recording a better and more accurate experience.
Finally, one of the quirks of Logic's Low Latency mode is level inconsistencies. (Probably due to level differences the disabled plugins cause before/after processing). An intelligent implementation of this would be able to account for level differences behind the scenes... It's not essential by any stretch... But would be a slick bonus...
FINAL CLARIFICATIONS:
Just to be sure the concept is clear... I'm not suggesting Studio One would drop the buffer to nearly zero latency... The device block size would still be the size used... "No Latency Mode" would simply prevent latency to be added to the block size when recording or monitoring, other than the desired latency threshold the user has set..