postgis24_* package

Just curious how the postgis package upgrades are intended to work ? It seems
to me we need to (for example) install postgis24_96, then run
postgis_upgrade.sql (or UPGRADE EXTENSION). It looks like PG10 only supported
by postgis24 packages, so that's a needed step in pg_upgrade to PG10 (else PG
upgrade will die after pg_dump --section=pre-data with an error in
loadable_libraries.txt0

Ideally the package would be installable alongside postgis23_96, to avoid
backends being unable to load postgis library (or loading an incompatible
library, crashing, taking down the server and rest of the backends).

However they're not co-installable:
[pryzbyj(at)database ~]$ rpm -qa |grep postgis
postgis23_96-2.3.3-1.rhel6.x86_64
[pryzbyj(at)database ~]$ sudo yum install postgis24_96
file /usr/pgsql-9.6/lib/liblwgeom.so from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/address_standardizer.control from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/address_standardizer.sql from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/address_standardizer_data_us.control from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/postgis.control from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/postgis_tiger_geocoder.control from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/postgis_tiger_geocoder.sql from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64
file /usr/pgsql-9.6/share/extension/postgis_topology.control from install of postgis24_96-2.4.0-1.rhel6.x86_64 conflicts with file from package postgis23_96-2.3.3-1.rhel6.x86_64

Okay, if they're no co-installable, that's fine. But why does the package name
include the postgis version then ? For the postgresql96 style package names,
that was to allow co-installation.

Further, how do I actually install postgis24_96 ? Do I actually have to run
"rpm -e postgis23_96" first ? Or is some particular yum incanatation intended
to handle that ? I'm more familiar with Debian's packages, where the file
overlap would've been declated with "Conflicts" metadata (probably against a
postgis-postgresql96 virtual package). And file being allowed to be replaced
would've been declated with "Replaces" (but maybe not here, since it can and
will cause the server to crash). And "Conflicts+Replaces" would've been
declared to allow installing postgis24_10, but requiring the removal of the old
package. I think conflicts alone is sufficient and ideal for this purpose.
https://www.debian.org/doc/debian-policy/#conflicting-binary-packages-conflicts

Under debian I would do "apt-get install postgis23_96- postgis24_10" to remove
one and install the other. I found yum has this syntax:
"sudo yum install -- -postgis23_96 postgis24_10", but it seems that means
"cancel installation sugggested by previous dependency/recommends/groupinstall"
rather than "uninstall". Is there a variation requiring removal ??

BTW this page still talks about PG10 beta:
https://yum.postgresql.org/

Also there's a stray/missing quote in the mailto link on this page:
https://yum.postgresql.org/news-10beta-ready-for-testing.php
">us</a>

Thanks,
Justin