The holes they drilled should help airflow and clouds. They shouldn't be creating a harsh flavor. With a dual coil set up, say at .7 (maybe?) you should be getting an excellent hit and plenty of clouds...but it's hard to diagnose because we can't see it!
Can you include some pictures of the top cap and the coil?
btw this is why you need a meter: It would make life simpler and safer for you if you knew exactly what that coil is!
Re building: It's easy and cheap. My b&m sells 28 gauge kanthal wire for $6. You can get organic cotton balls for $4-6. There are hundreds of videos on building on youtube, with clear instructions. Instead of paying the guy at the shop $3 for a single build, spend $10 and get enough materials to build a hundred coils of your own.
In case I forgot: Get a meter!!!!!! lol.
I went to one of my normal vape shops earlier and the guy who worked there who is always dripping with giant clouds, I asked if he would try mine and see if I was just doing something wrong, he said the build I had was very restrictive to him, and he blew bigger clouds than I did, but nothing big, he actually re-drilled 2 of my holes (free) to make them bigger and it made it a better vape, cleaner taste, smoother, and a bigger vape (not crazy but decent enough). He said they built mine with dual micro coils and they probably used a 28 gauge and should try a 24 gauge instead but he vapes a lot lower than I want to get in to. The other shop the guy told me a 28 gauge is the best for the nimbus (clone). My ohm reading when he tested it was around 4.65-4.67 ohms.
I did a get voltage and ohm reader dual reader, got the organic cotton balls for a little under $4, and plan to get the kanthal wire soon to practice one of my local shops sells it so much cheaper than any other vape store near me it's $9 for a spool of 25 $13.50 for a spool of 50 and $15 for a spool of 100 (inches I believe)? Since I think feet wouldn't be right. Hoping this is the right one and need to figure out the best gauge.
Gauges: 24, 26, 28, 30, 32
Kanthal A1
Kanthal A1 is for use at temperatures up to 1400°C (2550°F).
Kanthal A1
Melting Temperature: 1500°C (2732°F)
Maximum Operating Temperature: 1400°C (2550°F)
Density: 0.256 lbs/cubic in.
Specific heat capacity @ 68°F: 0.11 Btu/lb°F