Finally got back to this.
I installed 2.8.2 with no errors, the manager came up and I could log in.
Next I uploaded the assets folder from the 2.5.0 site, manually cleared the core/cache folder, imported the database from the 2.5.0 site and reran the setup. No errors during the install process. Front-end comes up, mostly. The manager produces a 500 error.
Here are the two logs from the server:
Error Log
[2021-05-16 14:00:35] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 644) Could not load class: Ace from ace.
[2021-05-16 14:00:35] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 1248) Problem getting service ace, instance of class Ace, from path /home/xxxxxxxxx/public_html/core/components/ace/model/ace/
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/cache/includes/elements/modsnippet/28.include.cache.php : 39) PHP warning: include_once(/home/xxxxxxxxx/public_html/core/components/wayfinder/wayfinder.class.php): failed to open stream: No such file or directory
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/cache/includes/elements/modsnippet/28.include.cache.php : 39) PHP warning: include_once(): Failed opening ‘/home/xxxxxxxxx/public_html/core/components/wayfinder/wayfinder.class.php’ for inclusion (include_path=’.:/opt/alt/php73/usr/share/pear’)
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 644) Could not load class: Wayfinder from wayfinder.
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/cache/includes/elements/modsnippet/28.include.cache.php : 39) PHP warning: include_once(/home/xxxxxxxxx/public_html/core/components/wayfinder/wayfinder.class.php): failed to open stream: No such file or directory
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/cache/includes/elements/modsnippet/28.include.cache.php : 39) PHP warning: include_once(): Failed opening ‘/home/xxxxxxxxx/public_html/core/components/wayfinder/wayfinder.class.php’ for inclusion (include_path=’.:/opt/alt/php73/usr/share/pear’)
[2021-05-16 14:01:52] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 644) Could not load class: Wayfinder from wayfinder.
[2021-05-16 14:02:07] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 644) Could not load class: Ace from ace.
[2021-05-16 14:02:07] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/xpdo.class.php : 1248) Problem getting service ace, instance of class Ace, from path /home/xxxxxxxxx/public_html/core/components/ace/model/ace/
Install Log
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/3f98f496e2400ccc4a58f556d84c9ed7/0/ to /home/xxxxxxxxx/public_html/index.php
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/3f98f496e2400ccc4a58f556d84c9ed7/1/ to /home/xxxxxxxxx/public_html/ht.access
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/0/ to /home/xxxxxxxxx/public_html/manager/assets
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/1/ to /home/xxxxxxxxx/public_html/manager/controllers
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/2/ to /home/xxxxxxxxx/public_html/manager/templates
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/3/ to /home/xxxxxxxxx/public_html/manager/min
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/4/ to /home/xxxxxxxxx/public_html/manager/ht.access
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdovehicle.class.php : 182) Could not copy /home/xxxxxxxxx/public_html/core/packages/core/modContext/5830943cddc46de5db5c0ab6294f8520/5/ to /home/xxxxxxxxx/public_html/manager/index.php
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdofilevehicle.class.php : 104) Could not install files from /home/xxxxxxxxx/public_html/core/packages/core/xPDOFileVehicle/3e0c6aeb6d0f68186afe20d6e293b3e6/ to /home/xxxxxxxxx/public_html/connectors/
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdofilevehicle.class.php : 104) Could not install files from /home/xxxxxxxxx/public_html/core/packages/core/xPDOFileVehicle/79d72b80fb743f09bd36baeffb814923/ to /home/xxxxxxxxx/public_html/connectors/
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdofilevehicle.class.php : 104) Could not install files from /home/xxxxxxxxx/public_html/core/packages/core/xPDOFileVehicle/c9de21b807e7754527c659be1e6b2ddd/ to /home/xxxxxxxxx/public_html/connectors/
[2021-05-16 14:00:24] (ERROR @ /home/xxxxxxxxx/public_html/core/xpdo/transport/xpdofilevehicle.class.php : 104) Could not install files from /home/xxxxxxxxx/public_html/core/packages/core/xPDOFileVehicle/433ea1821a2a94e2fcc367c7784a3d0e/ to /home/xxxxxxxxx/public_html/connectors/