"Founders cash in pretty much signals cashing in and raise...

"Founders cash in pretty much signals cashing in and raise cash."

It doesn't signal anything of the kind.
The founders have done precisely what the board asked them to do back in 2018..

'Mr Peter Kempen Pro Medicus Chairman said “We announced in February 2018 that theBoard had encouraged the founders to consider selling up to 3 million shares each, in order toimprove the liquidity in the company’s shares. This latest transaction completes that process.The sale, to a number of local institutions, was done “at market” which reflects the verystrong underlying demand for the company’s shares.”
Dr Hupert and Mr Hall re-affirmed that they do not intend to sell any further shares in PME inthe foreseeable future.'

Even after the sales by the Founders, PME would still have have one of the biggest percentages of shares held by board members of all the companies in the ASX 200.
Can anyone suggest a more tightly owned ASX200 stock?

The sharp drop in the short interest in PME in the chart below must have been really painful for somebody.
About 1%, of the sharp 1.4% drop in short interest occurred on Friday Feb 19.
That means that they were covering on a day when the shares traded between $46.11 and $47.55.
If the shorter had held the position since 13 Jan, that's $20m down the gurgler, just on the shorts that they covered on Feb 19 & 22.
Wouldn't that make your eyes water.

(BTW, For some reason, the Shortman charts do not seem to show figure that is published by ASIC for the short positions as of each Friday. In the case of the chart below, it goes straight from 4.39% on Feb 18 to 3.02% on Feb 22. I had to go and dig out the figure for Feb 19 myself, which was 3.384%.)