I re-ran the test as follows to actually test the server side with only the packaged executables.

I used this command for the server side:

/usr/bin/openssl s_server -key key.pem -cert cert.pem -status_file openssl-1.1.1/test/recipes/ocsp-response.der -Verify 5

with ldd showing it loading its ssl & crypt libraries from /usr/lib/x86_64-linux-gnu:

ldd /usr/bin/openmssl
        linux-vdso.so.1 (0x00007ffe6ee65000)                                                                                                                                            
        libssl.so.1.1 => /usr/lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f44027c4000)                                                                                                   
        libcrypto.so.1.1 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f44022f9000)    
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f44020da000)                                                                   
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4401ce9000)                                                                                         
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f4401ae5000)                                                                             
        /lib64/ld-linux-x86-64.so.2 (0x00007f4402d04000)    

I built the client from 18.06.16 source with tracing enabled and used it for both tests and ran it with this command: 

LD_LIBRARY_PATH=openssl-1.1.1/build_shared openssl-1.1.1/build_shared/apps/openssl s_client -status -trace -cert cert.pem -key key.pem

with ldd showing it loading its own libraries:

LD_LIBRARY_PATH=openssl-1.1.1/build_shared ldd openssl-1.1.1/build_shared/apps/openssl
        linux-vdso.so.1 (0x00007fff51ff9000)
        libssl.so.1.1 => openssl-1.1.1/build_shared/libssl.so.1.1 (0x00007fc8c28b4000)
        libcrypto.so.1.1 => openssl-1.1.1/build_shared/libcrypto.so.1.1 (0x00007fc8c23e9000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fc8c21ca000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fc8c1dd9000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fc8c1bd5000)
        /lib64/ld-linux-x86-64.so.2 (0x00007fc8c2dfe000)

The following logs show the difference between having:
ii  openssl                                        1.1.1-1ubuntu2.1~18.04.15    amd64                        Secure Sockets Layer toolkit - cryptographic utility
and having:
ii  openssl                                        1.1.1-1ubuntu2.1~18.04.16    amd64                        Secure Sockets Layer toolkit - cryptographic utility

ubuntu@bionic-lp-1940141:~$ grep -B1 -A4 CertificateRequest s_client-18.04.16-from-source-with-trace_server-18.04.15-from-package.log
  Inner Content Type = Handshake (22)
    CertificateRequest, Length=1570
      request_context (len=0):
      extensions, length = 1567
        extension_type=status_request(5), length=1521
          0000 - 01 00 05 ed 30 82 05 e9-0a 01 00 a0 82 05 e2   ....0..........

ubuntu@bionic-lp-1940141:~$ grep -B1 -A4 CertificateRequest s_client-18.04.16-from-source-with-trace_server-18.04.16-proposed-from-package.log
  Inner Content Type = Handshake (22)
    CertificateRequest, Length=45
      request_context (len=0):
      extensions, length = 42
        extension_type=signature_algorithms(13), length=38
          ecdsa_secp256r1_sha256 (0x0403)

This is indicative of the fix working.