WYSIWYG at tournaments

Sorry if this is in the wrong place but I'm not 100% sure where else it should go. I've been getting back into 40k and building up a Dark Eldar force over the last year or so after having not really played since 3rd/4th edition. The idea is to eventually be able to take my stuff to compete in tournaments but I've been hearing reports about how some tournaments are extremely strict on your units being modeled with the wargear you've equipped them with in your list. I guess it's different depending on where you're playing but I can see WYSIWYG enforcement being a bit of a problem considering I didn't really think to magnetize and built all my vehicles with the weapons I would have chosen for them last edition (triple Dark Lance Ravagers, Venoms and RWJFs with splinter cannon upgrades etc) and they aren't necessarily the same choices I'd make now.

I guess what I'm asking is how often those of you who attend tournaments are faced with rules that state models must be WYSIWYG. Should I be concerned about changing my models to perfectly reflect my lists or will it likely not be an issue?

I have never had it be an issue.

It really depends on what you are trying to proxy.

No one knows the difference between a heat lance and a haywire blaster, for example. But a cannon counting as two rifles is a bit more of a stretch.

With the dark lance/disintegrators, you can easily clip and magnetize the barrels.

I rarely face full wysiwyg. In that decent and minimal conversion is enough.
Counts as is allowed in the vast majority, but with the requirement is must be simple, clear and universal.
So "all my scourge special weapons are blaster" , "all my heat lances are haywire blasters" is cool.

It's not a perfect answer, but it truly depends on your TOs. In my area it's not a problem, so long as people aren't aggressively abusing it by trying to pass off a grot as a meganob or something asinine like that. General attitude is if it looks like a special weapon, it is whatever you say it is - the key factor is quick identification of regular vs special weapons.