Batch DNS inquiries stall

After spending a couple of days experimenting with the overall script in the hope of finding a way of avoiding the stalls
that prevented me from using dig -x to take advantage of its output details without spending several hours at a time
watching for the recurring stalls in the progression of the output of the script, it dawned on me that I might build the
solution into the dig command. The solution:
dig -x +tries=10 100.24.191.100 >> A-16MB.txt ;
dig -x +tries=10 100.24.191.101 >> A-16MB.txt ;
dig -x +tries=10 100.24.191.102 >> A-16MB.txt ;
...
dig -x +tries=10 98.185.162.7 >> A-16MB.txt ;
dig -x +tries=10 98.185.162.8 >> A-16MB.txt ;
dig -x +tries=10 98.185.162.9 >> A-16MB.txt ;
awk '{print $0}' A-16MB.txt | grep -A 16 "ANSWER SECTION" '-' | sed 's/;; ANSWER SECTION://g' | awk 'NF=5 {print $5,$1}' | sed 's/\.0\/24//g'| grep "in-addr.arpa" > Temp-Edit.txt ;
paste -d ' ' <(awk '{print $1}' Temp-Edit.txt) <(awk '{print $2}' Temp-Edit.txt | sed 's/\.in-addr\.arpa\.//g' | sed 's/\./\t/g' | awk '{print $4"."$3"."$2"."$1}') > B-16MB-edit.txt ; rm Temp-Edit.txt ;
The next-to-last line of the overall script is meant to process the entire output all-at-once instead of repeating
the script after every DNS lookup, but it's getting stymied by the ends-of-file that are built into the dig responses.
grep "<<>>" A-16MB.txt
captures only the beginning of every dig response, but does reach every one of the dig responses; however:
grep -A 100 "<<>>" A-16MB.txt
captures what may be ends-of-file within those dig responses, so the ensuing processing
...| grep -A 16 "ANSWER SECTION" '-' | sed 's/;; ANSWER SECTION://g' | awk 'NF=5 {print $5,$1}' | sed 's/\.0\/24//g'| grep "in-addr.arpa" > Temp-Edit.txt<
is getting blocked, leaving Temp-Edit.txt woefully underpopulated.
The good news is that all of the DNS lookups completed without my intervention. The bad news is that there is no such
thing as an end-of-file character ... Is there anything that can be done with sed in this regard ?

Looks as though I'll have to do the processing one-at-a-time and hope that the required extra seven tries in the dig
command will still be enough to keep it going until we can perfect the rattle-the-cage-script.

Upon further investigation, dig -x resolves only the first IPv4 address in the list as though I'm blocked.
With nslookup, progress is still possible ...

Success !
nslookup -retry=10 100.24.191.100 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
nslookup -retry=10 100.24.191.101 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
nslookup -retry=10 100.24.191.102 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
...
nslookup -retry=10 98.185.162.7 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
nslookup -retry=10 98.185.162.8 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
nslookup -retry=10 98.185.162.9 | grep "in-addr.arpa" | awk '{print $4,$1}' | sed 's/\.0\/24//g' >> A-16MB-1015.txt ;
grep "in-addr.arpa" A-16MB-1015.txt > Temp-Edit-1015.txt ;
paste -d ' ' <(awk '{print $1}' Temp-Edit-1015.txt) <(awk '{print $2}' Temp-Edit-1015.txt | sed 's/\.in-addr\.arpa\.//g' | sed 's/\./\t/g' | awk '{print $4"."$3"."$2"."$1}') > A-16MB-edit-1015.txt ; rm Temp-Edit-1015.txt ;
While very slow at times when retrying, the script updated at least the output time frequently, finished, and processed
the output file to a make list of hostnames and their IPv4 addresses, 70% as many as the original list of IPv4 addresses.