This was part of a google summer of code. This requires change in the core and it wasn't "production ready" and hasn't been merged. For what I recall, they were a few tweaks that were "big gain", like automatically generate the input fields (most of?) so they use the same html structure and classes than bootstrap.
It would be great to complete the project ...
Problem a result of using Shoreditch as Civi theme. Same problem exhibited when using API Explorer UI.
SearchKit and API Explorer both use bootstrap theme which seems to have conflict with Shoreditch.
Only solution found was to uninstall Shoreditch. (Disabling shoreditch was not sufficient)
The public-facing donation and event pages inherit their look and feel from the Wordpress theme. If there's overlapping text, it can't be fixed within CiviCRM; it must be fixed within WordPress. You should be able to confirm this by loading a Wordpress default theme like twentyseventeen on your site (ideally a test version of your site), and the problem ...
I'm still finding my way around civicrm so it looks like no style was applied to civicrm or the template css file takes precedence. I used some of the style setting from civicrm.css in the custom css section of the template and this fixed the issue. There is problem a cleaner way to use the civicrm style sheet but for now this worked for me.