Flowers attracting smaller Coleoptera (Nitidulidae and Glaphyridae)

You are going to have to refine this. This is not a typical beetle flower.
A typical beetle flower has a large landing platform, and lots of anthers onto which the beetles land and feed: a mess and soil type situation. Examples include larger daisies and proteas, but also tropical large flowerheads such as palms and magnolias.
What you are describing here is a very specialist kind of beetle flower: probably only applicable to a few Hopliinids
There are other types of beetle flowers: carrion flowers, traps, bowls with towers (e.g Arum: slide in and climb out over stigma and then over pollen areas).

Hi Tony,

I've done a bit more research on beetle pollination
You are quite correct in that the families with large individuals such as Bombyllidae need a visually distinguishable and sturdy enough flower platform to land on. A prominent example would be a few Polygala and Vigna species in Fabaceae. However, it seems that there are many flowers (some with generalist pollination syndromes) which cater to the smaller families as well such as Nitidulidae

The general features which attract these Families are primarily bowl shaped flowers with more or less exposed reproductive organs, deeper reserves of nectar, and weak scents with highly variable chemistry, but this is true only so far as the temperate Mediterranean regions are concerned. In the tropics and other area's the syndromes and pollination systems are highly variable and can include flat-topped brush inflorescences and flowers with deep, trapping chambers

Interesting to note is that the colour of the perianth's centre also plays a very important role in the Beetle-pollinated flowers of the temperate regions, and may very well be linked to eliciting sexual behaviour

Source: Dobson HM, 'The Biology of Floral Scent', 2006