You are probably right, though I've used HKS filters previously without any issue, and the one I bought was a tenner so I'm not expecting much from it. This air filter is not intended for long term use, it is still better then running no air filter whilst I'm moving the car around the unit.
The issue I have is that the NA stock airbox I have does not fit in it's usual place, given that there is now an intercooler pipe that comes across onto the front of the air intake area.
I need to source a TT stock airbox soon, as the outlet pipe on those is at a different angle and will fit in with the current pipework setup. Or, I need to spent the equivalent of a stock TT airbox on new hoses for the intercooler and air intake piping in order to fit the NA airbox.
Anyway it will be sorted out in due course after all the paintwork etc.
To summarize, not really. No different to removing/installing a 2JZGE/GTE. Everything bolts into place where it should.
The only major difference is that you need to adapt some of the plugs/pins from the 1JZGTE engine loom to fit the MKIV Supra interior loom.