In case this is something that's reasonably easy to locate and eliminate. It appears the scripting overhead has taken a large jump between v7.52 and v7.53, as demonstrated by running this bare-bones while() loop on both versions:

//!var %i 99999 , %t $ticks | !while (%i) { !dec %i } | !echo -a $calc($ticks - %t) ms

Repeating this consistently shows me the time increasing by 15%, and I had someone else seeing a difference as high as 30% jump. I didn't see a change in either version's time after giving the old version the same scripts and turning /remote off.

It's possible this is related to the issue I reported in the hashtable thread where I was seeing a 15% slowdown in beta 1438 comparted to 7.52-no-beta.

That 1438 beta was prior to the first changes related to FNV1a, and was having most of the slowdown I was seeing when comparing the no-beta vs the 1897 beta which had FNV1a.