This feature is used only for TCH allocation & not for SDCCH.
So,if your Rx_Lev of TCH is lower than DL_Rx_Lev(min),your SDCCH will get released(T3101 expiry).
If your SDCCH Drop rate includes T3101 expiry,you will observe huge SDCCH Drops Rate.
Since you have set RXTA=1,no impact on HOSR.
But if you keep RXTA=2,your HO may get dropped if it doesn’t meet the DL_Rx_Lev(min) criteria and no other suitable neighbour cells.