Btukfyl

It might be the case that someone uses to engage into entertaining with Dhamma reads and talks in his working time, or uses resources of other for such, yet not really given, just like one may chat or do what ever privat while in the office.

What might be the effects of such deeds? Would it be possible to get long term benefit from doing so? Possible to gain good while thinking, acting, like a thief?

[Note that this is not given for trade, exchange, stacks, Buddh-ism or other entertaining that keeps one caught but for liberation.]

Bad kamma. The Buddha said:

The servants and employees thus ministered to as the Nadir by their
master show their compassion to him in five ways:

(i) they rise before him, (ii) they go to sleep after him, (iii) they
take only what is given, (iv) they perform their duties well, (v) they
uphold his good name and fame.

DN 31

But if a person is self-employed and their work day does not require 8 hours work per day then its no problem. If the self-employed person has free time during their work day in their office then discussing Dhamma is good kamma (especially if they can teach an undisciplined bad puttujjana monk).

Most employees are usually allowed some small pockets of free time, that they may use to read something related to Buddhism. That's fine. Most people use such legitimate small pockets of free time to look at social media, or text their family and friends outside of work.

However, browsing Dhamma or social media during the time they are supposed to be working is a kind of stealing - taking something that is not given to them. Employees have contractually given up a lot of their time and effort to their employer in exchange for remuneration. So, not giving one's time and effort as promised is a kind of stealing.

Stealing of course violates one of the five precepts, but I won't put browsing Dhamma during working time in a full time employment, in the same category as stealing the little money that a poor family has, to feed themselves.

What kind of effect would it have? Well, employees may get fired and lose their source of income. They would also lose their reputation.

I think this is a good example of the practice of heedfulness (appamada). We should be ever heedful and mindful of our duties and responsibilities, as well as the five precepts. It's true that one may not be able to fulfill the five precepts perfectly, but at least one should try his or her best.

Talking about fulfilling the precepts perfectly, this answer about stealing a sniff of the scent of flowers (from SN 9.14) is very apt for this case. Using the legitimate small pockets of free time during working time to read the Dhamma is like stealing a sniff of the scent of flowers. Those aiming for perfection in virtue (paramita or parami) should avoid it. But then again, those aiming for perfection in virtue may be better suited to the monastic life than the lay life.