You’re not taking advantage of hardware serial at all unless you send a byte at a time.
Otherwise it’s blocking just like software serial. A for next loop sending hardware serial will also block just the same.

Code:
atoj var byte[8]
index var byte
serbuff var byte
to send continuously:

mainloop:

‘ your program

if index > 7 then
index = 0’
endif

if index < 8 then
serbuff = atoj[index]
hserout[serbuff]
index = index + 1
endif

goto mainloop
Don’t write into the buffer while index is less than 8.