What's the influence of relocation on a solar return chart?

I've read so many different opinions on the matter.
Some say that the intention is a powerful tool, powerful enough to sustain its influence of a temporary relocation throughout a whole year.

Others claim that the location of your residence trumps any trips, vacations, excursions to other places.

Being born in mid-August, I often spent my birthdays outside of my birthplace. (not far enough to potentially make a significant difference though, I'll have to check for a year or two when I went abroad).
When the first Saturn return ended, I moved abroad and started using my new town as a reference place for calculating my Solar returns.

Now, this year I am about to spend my birthday in a foreign country on a short business trip. What am I to put as a reference place? My residence or the town where I'll actually celebrate my b-day?

Here's what's been bothering me.
These last couple of years, my Solar sun has been "dancing" between the 12th and the 4th house. It's not a pleasant thing, I'll tell you that, but I have accepted it and did my best.
This was the first year where my solar Sun would be in the 1st house and the next year in the 10th.

My life was spontaneously reflecting this energy. I started changing some wrong self-defeating childhood patterns, building my self-confidence, getting in touch with my emotions, needs and making plans... This was the first time I stood up for myself at work and got an opportunity to present our firm on a congress in a foreign country... and what do I get (if I use relocation for my solar) my Sun in the 12th... again. Not to mention that it is in conjuction with Mars.

So, how important is the relocation?

Thanx!

Most astrologers choose place of residence for the year, not the day.
If you were in a diff place with intention to reisde there perm then use that location.

If you test the exp of reloc for bday and find it works for you then use it.
Some claim this is very effective for them.

If you reside far from birth city, consider relocating birth chart and following transits and prog based on it in addn to natal.

So what have you observed?

Thank you Frog for your reply, that I haven't seen until now!
Which is interesting because, now, six months after my birthday, I can answer your question about what I have observed.

It seems to me that, as you said, place of residence should indeed be used as a reference place.

My solar year has been, so far, marked by the Sun and Mars in the 1st and not in the 12th where they are if I use the place where I spent a couple of days for my birthday:
- I'm more focused on myself and my needs (something which I have always had trouble with)
- slight weight-gain
- Health-issues (also related to Pluto in 6th!)

Venus (12th) opposite Pluto (6th)
- positive change, healing and transformation on both personal level (started doing yoga and meditating) and in marriage (my husband joined me )

Moon in the 10th, heavily aspected by Mercury, Neptune
- at work from the behind the scenes where I usually do my job, I had to take the stage before an audience (literally, on the very morning of my birthday)
- square with Neptune: it was difficult for my superiors to see the importance of my work and accept good ideas
- square with Mercury: I'm making a conscious effort to bring to light and change old bad, deeply rooted habits that affect mostly my professional life

Neptune in the 8th
I have used this energy for spiritual development

Saturn in the 5th
-I'm not in menopause yet (as sometimes this solar position can indicate) but I'm definitely starting to feel changes in this area.
- Seriously thinking about adoption
- I became more serious in regards to my creative expression
- I haven't experienced bad influence on my love life, if anything my marriage changed for the better

Jupiter in the 3rd
- I finally passed a difficult language exam I had been putting off for a very, very long time
- Got some good ideas about the future direction of some additional training/studies I might undertake
- I published a website for my husband and started working on mine

Mercury in the 2nd
- I haven't earned money from sales, but I continued to teach (languages and math)
- I experienced some fluctuations leading to less money earned

Pluto in the 6th
- I started adopting more healthy habits that lead to both spiritual and physical change, sometime before I started having health issues.
- I was diagnosed with yet another autoimmune disease (my Chiron is natally in the 6th house) and I'm still visiting doctors, doing tests etc.

Thank you again, since I will probably spend my birthday the same way I did last year, now I'll now where to look