Recommended upgrade path from CMS Builder 3.54 / PHP 7.4 to current version / PHP 8.x

Hi,

I’m preparing to upgrade a fairly old but fully functional CMS Builder installation and would appreciate advice from anyone who has done a similar migration.

Current setup:

• CMS Builder v3.54 (Build 2280)
• PHP 7.4.33
• MariaDB 10.11.19
• Apache

The installation includes several custom sections, custom viewers, and some custom PHP code.

I have already created a complete staging copy, including files and database, so I'll do all testing there before touching production.

My main question is about the safest upgrade sequence.

Would you recommend:

A. Upgrading CMS Builder first while still on PHP 7.4, then moving to PHP 8.x
or
B. Moving directly to a newer CMS Builder release together with PHP 8.x?

I was considering using an intermediate CMS Builder release such as v3.59, since it appears to be one of the last versions compatible with PHP 7.x, but I would be very interested to hear what others have done in practice. Any advice and assistance would be greatly appreciated. 

Kind regards.

Andreas Lazaris