I've been modifying the search widget for a decade to move the button from inline to the next. Having a bit of spare head space I wondered if it could be done with css. The solution was to use the existing class for the button and add [display:block]. There was then the extra positioning using the subsequent three lines.
Having decided to upgrade hosting to move up from php 5.4.41 I am now able to install b2evo 6.10.6 and up.
It was a bit of effort starting with by installing a security certificate I had to edit post references to https. A laborious job that led me think I could just hack the database. So downloaded it, run through a text editor, namely notepad+ and replaced all [http:] with [https:]. The colon is important as it is conceivable that http may be mentioned as text not a parameter value for a link.
There were also layout problems that arose whilst getting the new sever to work, by transferring version 6.10.5 before upgrading. More details to follow, maybe.
Versions: (6.10.6 Line 220) Add