/usr/share/crypto-policies/back-ends/FUTURE
NameSizeModeActions
bind.config1240644editdlrm
gnutls.config5290644editdlrm
java.config6570644editdlrm
krb5.config1070644editdlrm
libreswan.config2010644editdlrm
libssh.config10650644editdlrm
nss.config3470644editdlrm
openssh.config9750644editdlrm
opensshserver.config13440644editdlrm
openssl.config1650644editdlrm
opensslcnf.config5800644editdlrm
Edit: /usr/share/crypto-policies/back-ends/FUTURE/libreswan.config (201B)
conn %default ikev2=insist pfs=yes ike=aes_gcm256-sha2_512+sha2_256-dh19+dh20+dh21+dh15+dh16+dh18,chacha20_poly1305-sha2_512+sha2_256-dh19+dh20+dh21+dh15+dh16+dh18 esp=aes_gcm256,chacha20_poly1305