Video source: https://reaperblog.net/2018/02/new-features-in-reaper-5-75/

v5.75 - February 17 2018
+ Automation items: do not automatically extend automation items that match the time selection (to enable time selection autopunch behavior) [p=1936848]
+ Automation items: fix automation items being left behind when key modifiers change during media item edit [t=200768]
+ Batch converter: avoid possible glitch at end of conversion for items with take FX
+ Batch converter: fix incorrect sample rate used when processing item with take FX
+ Control surfaces: do not auto-close http/OSC control surfaces when inactive
+ Envelopes: when using "preserve edge points" mouse modifier, prevent unnecessary left edge point if previous point shape is square
+ Extensions: do not load project template after successfully importing a project via extension [t=202610]
+ FX: ensure no feedback loop created when building multichannel routing on a folder [t=201177]
+ FX: fix channel behavior when loading FX chain via SWS resources [p=1951546]
+ FX: fix looping PDC automation issues near loop point [t=200899]
+ FX: fix wet/dry automation issue with PDC [t=201087]
+ FX: use variable I/O for Audio Unit plug-ins that do not support kAudioUnitProperty_SupportedNumChannels
+ FX: list newly scanned plugiins in the "New" category for 24 hours
+ Grid: display arrange view grid lines and ruler markings more consistently with linear tempo changes [p=1924259]
+ Grid: optionally divide arrange view vertically by measures
+ Groups: allow theming of colors for groups 33-64
+ Install: do not update last-modified timestamp on unchanged InstallData files (such as JSFX)
+ MIDI editor: fix CC lane drawing issues with looped items
+ MIDI: improve pixel accuracy and overall display of notes and CC in the arrange view [t=201105]
+ MIDI: add preference to display multiple CC lanes in the arrange view, and/or combine all CC data into a single lane
+ MIDI: treat type 0 files with meta-events as multichannel files on import; if configured, prompt to import meta-events and channel MIDI as separate tracks [t=201510]
+ Media: when replacing source media, reset start offset if it is no longer within the source media length [t=203231]
+ Mouse modifiers: new modifier to add or toggle media items or MIDI notes to selection, and set time selection to selected items or notes
+ MusicXML: fix manual quantizing after import [t=202244]
+ OSC: allow setting /track/monitor mode directly (rather than just cycling) [p=1914163]
+ ReaControlMIDI: support sample-accurate automation playback
+ ReaScript: TrackFX_GetNamedConfigParm() can query pdc, input/output pin names
+ ReaScript: allow very small sizes for custom UIs
+ ReaScript: fix incorrect sample rate used when processing take FX via audio accessors
+ ReaScript: improve syntax highlight of non-typical Lua function calls [t=203219]
+ Recording: latency-compensate input-FX delay [t=200916]
+ Regions: copy regions without splitting the original media items [p=1902899]
+ Regions: fix some envelope issues that arise when copying/moving regions [p=1947748]
+ Solo: improve behavior with routing and folders [t=199396]
+ Subprojects: add action to save project and render RPP-PROX for non-subprojects
+ Subprojects: add option to prevent automatic subproject rendering
+ Subprojects: add option to prompt on background subproject rendering
+ Subprojects: copy markers/regions when moving track to subproject
+ Subprojects: copy grid/framerate settings when moving tracks/items to subproject
+ Super8: improve edge trimming
+ Take FX: fix issues when rendering take FX as new take [p=1937158]
+ Take pan: produce stereo output when rendering mono items with pan or pan envelopes
+ Tempo envelope: add action to insert tempo marker at cursor, without opening the tempo edit dialog
+ Undo: avoid over-compaction of undo history [p=1936784]
+ Video: add (otherwise undocumented) refresh_ms= ini file tweak
+ VST: do not update VST3 preset list in response to parameter names changing [p=1924970]
+ VST: inform VST3 plug-ins of multichannel context even if the plug-in does not adjust its I/O configuration in response
+ VST: prevent VST3 multichannel plug-ins from running in mono on stereo tracks [p=1945285]
+ VST: avoid incorrect offline-processing notifications on plug-in load
+ Windows: fix topmost pin state remembering when using non-latin pathnames [p=1926485]
+ Windows: show top-level expand/collapse button in Add FX dialog
+ macOS: preserve track I/O window position when auto-resizing