You could add some screenshots as an evidence, what kind of advertisements and which features are hidden in the premium version?
Actually a plugin developer don’t need to add advertisements for his other plugins everything is in the plugins search section. I am sure you have some kind of misunderstanding.
I have carefully checked all the setting pages and didn’t find any ads of any other plugin, and also I didn’t find any hidden feature. Please help me to sort these two issues out, ultimately you are helping me to improve this plugin. If you noticed something, let me know so I can remove the things which are annoying the plugin users, actually nobody reported such things before you.
There is only one feature which was required to sort the categories for the users convenience “WP Sort Order” add given purposely on the stock locations list, but that was not a kind of advertisement but a help without any hassle. And that is a free plugin too, don’t you like the opensource work and the efforts to make things easy to use?
If you cannot appreciate so kindly do not discourage or do not doubt on the good intentions behind the time invested in these opensource solutions.