I disabled cache plugin and triad to get similar results. I triad several times: disabled some of HMWP settings, disabled HMWP, use unchanged htaccess, different locations and etc. but couldn’t find a certain pattern. Here are some of tests:
You can see assets paths to know if HMWP was enabled or not.
Nearly 90% of tests finished in 8s and it didn’t matter if HMWP is enabled or not. I got 3s result once (disabled HMWP) but couldn’t get it again.
Of course, HMWP impacts speed but it’s in scale of milliseconds not several seconds. There are other things to be worry: your theme uses too many assets (say 8-10 times more than a standard theme).
You can test it yourself but do it several times to find a common pattern. (WP Super Cache is turned off to get a realistic result)