I did run the same speed test on the newest build of the tweak gravity branch, same blocklists, same Zero W with a 32 GB Class 10 SanDisk Ultra uSD card.
[i] Number of gravity domains: 3106983 (2137836 unique domains)
[i] Number of exact blacklisted domains: 10
[i] Number of regex blacklist filters: 29
[i] Number of exact whitelisted domains: 138
[i] Number of regex whitelist filters: 0
real 22m2.758s
user 9m2.923s
sys 2m12.282s
For comparison, the same run yesterday on the dev branch (without the gravity tweaks), took about 4 minutes longer.
[i] Number of gravity domains: 3100840 (2137802 unique domains)
real 25m56.066s