I find most of the heads come with a range of adaptors
however I did have problems with the Energenie heads, which needed spacers adding or removing, most well at least the other three I have used eQ-3, Kasa, and Wiser, they exercise and work out how far the plunger needs to travel, the cheapest as the time (2019) the eQ-3 (£15 each) has a code it displays if either under or over travel is detected.
They all seem to come with adaptors
and the Wiser was limited in the box, but it had details to send for free adaptors in the packaging should the ones in the box not work.
As to pure mechanical type, not found them that good, it seems one takes pot luck at setting, what good is *123456 on the side, I want some numbers I know what they mean, like 20ºC. I will admit battery life with Kasa seems short, the eQ-3 will last a year or more, and the Energenie often more than 2 years, the Wiser is too new to comment, took ages to even find battery state.

both fitted around March so did expect to see full batteries. But the cost of 20 x AA cells once a year is well worth it when it allows me only to heat rooms at the times they are in use, the annoying thing is to buy a TRV one gets a silly mechanical head which then goes straight in the bin.