Mel,
@bluter 's comment is valid and I've got some real concerns. Because you have perlite meeting, I mean touching, the soil on a broad surface it will act as the wick even though the supposed rez water level is kept technically below the perlite's top with a drain hole. Another thing to think of is that your soil will crush and compact the perlite over time, and potentially bring the soil down to the drain-hole's level, or lower, if perlite's not given some extra height above the hole.
Most importantly (though the sinking perlite could be pretty serious) I'm concerned that with the entire bottom surface area receiving wicking - because it's touching the perlite which will wick up past the drain hole, no sweat - that you will reach over-moist, under-aerated conditions. Perlite wicks extremely powerfully. My little baggy-pots that sit on perlite sacks in those clear containers (see my in recent posts on the SIP thread), they only work because the entire pot is porous material and of small volume, so with air coming in from all sides it means the water has enough oxygen in it that it doesn't matter how wet it gets, like DWC.
In your case the plastic pot will only have access to climate-gasses/oxygen via the top surface, possibly (likely) not enough to keep the bottom water/soil oxygenated or, alternately, aerated, and the perlite will wick up past any airgap attempt made with a drainhole.
A solution that I would prescribe would be to find a big plastic tote lid or otherwise large enough sheet of non-porous material and make a false floor out of it, drilled with lots of little holes, with a hole in the middle for the wick, which looks fine. You can prop the false floor up with PVC pipe stood vertically under it, or get some of that perforated pipe for drain fields. For your large pot size you should look for 6" perforated drain pipe, instead of the 4" usually used. Although the 4" will work great. False floors give you max rez volume as a side benefit.
As an aside, I've found that if you drill two drain/air gap holes, then you'll get lots of oxygenation/aeration generated from the cross flow between the drain holes. But you;ll still need a proper airgap. Another little trick to get some flow in that gap is to figure out at what height of your fill tube is located the air-gap, and drill a bunch of holes at that 1-2inch stretch so atmo-gasses can pass down the fill pipe and into the airgap, out the drain holes and the reverse.
Another solution would be to fill the bottom with capped-off sections of perforated drain pipe or drilled out PVC pieces laid horizontally. Capp off to keep dirt out. Then you can drop some perlite straight on top or just soil/perlite mix (1/3 perlite) That way you don't have to come up with the false floor piece and as long as the drain hole(s) are placed correctly leaving and inch of air in the tubes as it settles. There need to be large air voids between the soil and reservoir as much as possible and a pure perlite layer won't allow it, it will, ironically, wick up and fill with water, esp over time it will seem to get wetter and wetter without adding water as all the little voids fill slowly. it's kinda weird. This solution will have a smaller rez than a false floor, but still work extremely well.
Thirdly, you could find a bucket to turn upside down to create a large void, drill it with holes everywhere and one just large enough to fit your fill pipe, like
@AspenCultivator and Azimuth, and BudsBuddy.
Man, I hope you don't mind this and I hope I've explained what I see the problem being and why. You won't get a true airgap with that setup due to the perlite's wicking capacity and without the bottom can become
overwet with water that doesn't have enough oxygen in it. All SIPs are "overwet" at the bottom, it's just that they have a steady oxygen flow into that water. Root rot takes place when a root uses up all of the oxygen from the water in a location and then starts to die away. The problem this causes is, all can be fine until you have a nice mature plant that's constantly using more oxygen over a given time period and the demand level finally taps out the source's ability to re-oxygenate fast enough. This means everything seems ideal for months and you are cruising to a skookum harvest and then, BAM, root rot. It's one of those might/might not issues but because it's often 100% fatal and can often happen late in a grow, I feel pain like that ought not to be chanced.
Phew. I'll stop there. Man, I hope we're still friends! Let me know if I can help, happy to try to explain again if you thought it would help. Sorry to butt in, but you know...