For example, I'm building USDCAD (UTC+2) 5 minute strategies and have limited trading times to 03:00 to 21:00 with exit at end of day and a spread of 2. I've chosen this spread based on broker data that I've been collecting for many months.
If this feature was implemented I could set options up like this (based on UTC+2):
Start Time: 00:00 End Time: 01:00 - Spread = 8.0
Start Time: 01:00 End Time: 03:00 - Spread = 2.5
Start Time: 03:00 End Time: 21:00 - Spread = 2.0
Start Time: 21:00 End Time: 23:00 - Spread = 2.5
Start Time: 23:00 End Time: 00:00 - Spread = 3.0
This would allow me to be able to expand my trading times and for higher TF strategies I can see how they fare with rollover.
Rollover is always a precarious time with spreads widening significantly and if spread is always a set number, a trade may not be closed out or a new trade opened in backtests where there is no end of day exit or limited trading range set.