Making trailing SL as 2 ticks or 4 ticks is a backend issue and not a front end. if there are 1000 orders with 2 ticks TSL, every 2 seconds there will be 1000 new orders. That is just too much load for the system to take.
I am not saying it for all scrips .For example , for scrips below Rs.100 the range will be around two rupees and a daytrader can catch only 60 paisa to one rupee.
So a 2 point or 4 point trailing SL can save his capital especially if it is a Futures poistion .It will make a big difference to his trading .
But for all other scrips like above Rs.300 a 20 point move is ok because the range will be bigger .i.e 6-7 rupees.
Consider something like this : Trailing SL 2 % of the Scrips' LTP or 20 points whichever is lower ( rounded to nearest tick move say 5 paisa ) .
What you are saying is right for Nifty or big volume scrips the 4 point is too much to handle . What I am suggesting is based on scrip's price.
This way you can minimise the load , and save client's capital - I hope , that is ultimate purpose of introducing Bracket order .
Thanks again .