Entering Sweden with tourist visa while awaiting "researcher" permit

On the personal anecdotes side

I have personally applied for tourist visas to Sweden for other people WHILE the person in question simultaneously has some kind of long-term visa application in the works. Such as waiting for a residence permit (move to relative) decision and visiting as tourist during the decision time.

I've been the sponsor and in the application very clearly specified the reason and openly explaining the situation:

Due to the unknown length of time before a decision will be made on the [non-tourist application] ... would like to request a tourist visa for visiting in the meantime.

and

Should the mentioned [non-tourist application] require personal attendance at the Swedish embassy [applicant] will immediately return there.

So far successfully getting the applications for additional tourist visa approved and entering/exiting Sweden. The actual non-tourist permits have also been granted.

Background

This became "necessary" due to the extreme waiting times in getting decisions from Migrationsverket in 2015-2016 due to the influx of refugee cases to Sweden. Resulting in "estimated time to decision 6-24 months", which of course makes planning anything impossible.

People simultaneously entering on tourist visas doesn't seem that far-fetched then, even if it might technically be against the rules. I was told by Migrationsverket officials that this was not the way to do it, "The applicant must be reachable in the country of original application submission during the application processing time." and "The sponsor must be reachable in Sweden during the application processing time.". Maybe exceptional times made them realize the long waiting times required some allowances.

Again, this is purely personal experience (two cases), with no references to written rules. I am submitting it because the question requested "personal anecdotes".

I am asking this because I have been told on the phone by an official employee that "it is forbidden for one to enter the country while their residence permit application is being processed."

Tourist visas are under the authority of the Schengen Visa Code and there's nothing there about the impossibility of entering a given country while your resident permit is pending. I therefore presume the employee in question simply misunderstood your question and pointed out that your visa is not valid until it's been processed by the Migrationsverket. Traveling on other visas is a wholly different situation.

Will entering negatively impact the evaluation of my application?

If you want to be extra-sure your application won't be affected, simply fly into Sweden from a different Schengen state. There's currently no centralized database of entries and exits from the Schengen area, so there's no (easy) way for Swedish officials to even know you were inside the country.