Yes, that is possible.
In this case, after setting transmission enable status, modify the program to set an interrupt request flag when each transmit operation is completed.
This can trigger the same operation as when a transmission completion interrupt has occurred, and it can be implemented using an interrupt service routine that is common for all data transmit processing.
When the program sets a transmission completion interrupt request flag during initialization, the transmission completion interrupt request flag can be used as a transmission enable flag.
When doing this, be sure to mask transmission completion interrupts in cases where no data has been transmitted.
This will suppress triggering of useless interrupts.