Sancus: I'd recommend controlling for all possible variables, including weapon. Run your parse comparisons by only changing spells/procs, and absolutely nothing else. Don't provide a different weapon, or change anything other than the specific variables that need to be controlled for. I'd be interested to see your results by using Summoned: Daggers in both cases instead, while changing nothing other than spells on the pet. Run it to the extreme, with zero spell procs vs. all spell procs.
Here's the exact same proc test except with Summoned: Daggers equipped:
Combat Dummy Meda II in 3620s, 1.33B Damage @367.72K, 1.
Puksu = 1.33B@367.72K in 3620s
My pet performed 3.175 pierces per second and 0.198 backtabs per second,
declines of 16.4% and 14.7% compared to the non-proc tests. This is actually slightly worse swing rates vs the parse with proc weapons, but that's likely a combination of RNG and potential differences in serverside lag (it is Saturday now).
And here's the above scenario but with spellhold on (so
just proc buffs):
Combat Dummy Meda II in 3632s, 1.36B Damage @375.24K, 1.
Puksu = 1.36B@375.24K in 3632s
My pet performed 3.278 pierces per second and 0.203 backstabs per second,
declines of 13.7% and 12.5% compared to non-proc tests. This shows some improvement vs spellhold off (as expected), but still degradation vs avoiding procs.
The reason I included proc weapons was to properly include the sources of pet procs that people would typically use but have to avoid due to this bug: proc buffs, innate pet casting,
and proc weapons. Pet weapons are (counterintuitively) not an input into pet melee DPS beyond allowing Rogue pets to backstab from all angles (all of these parses were from the rear, so that effect doesn't matter). Therefore, the only impact of the weapon change was adding an additional proc, and using weapons with procs in the group game is exactly what someone would do if they were under the incorrect belief that procs only degraded pet melee in raids.
Anyhow, however you slice it, these parses show a clear, demonstrable impact of procs on pet melee rates in non-raid content. YMMV based on the quantity of procs you include and exogenous zone/serverside factors (this is a lag-induced bug after all), but it's simply not a raid-only phenomenon.