The phrase "almost constant use" is correct and usable in written English.
It can be used to describe a situation where something is used frequently but not continuously.
Example: "The software has been in almost constant use since its release, indicating its popularity among users."
Alternatives: "frequent use" or "regular use".
At one point, he wrote, "Brighton Beach Baths had more than 20 one-wall courts in almost constant use".
The consumer-goods giant now has over 70 TelePresence studios around the world, and says they are in almost constant use.
They are sold in bunches at roadside markets and are in almost constant use by workers in bright orange jumpsuits trying to keep the town's narrow roads free of desert sand.
That kind of overwrought narration makes some of these documentaries a slog, as does the almost constant use of slow motion; in the wild, it appears, nothing happens in real time.
It was in almost constant use as the 69-year-old strutted back and forth, clapping his hands thrusting his thick-lipped pout into the air.
In this method, combustion temperatures near the burners are maintained almost constant using a moveable multilayer heat-insulation device, which is installed on the fire-side of the furnace water-wall and can be moved up and down during operation.
Due to a variable gain in the lower half E-plane radiation pattern (elevation angle from 90 ∘ to −90∘), the antennas were placed in the car compartment so that the upper half E-plane radiation pattern (almost constant) was used.
The determined number of barcode clusters decreased significantly when the number of fixed bases used was small, and it became almost constant as the used number of fixed bases increased.
For the R1242G omega current, attempts to fit the almost constant omega current using Boltzmann fits yielded unrealistic values.
My subjective experience (after almost two months of constant use) is that its performance is on par with (not faster than) the 13-inch MacBook Pro Retina, which is packing a 2.4GHz Core i5 Haswell processor, a generation before Broadwell.
The first section of the novel occurs, I think, immediately after finishing work on Richard Yates, which was expected to be a time Paul would use to relax and maybe "calmly organize things in his room," but ended up being a time of extreme drug use and almost constant "partying".
