Via-in-Pad on 4-Layer PCB With SOT-23, SOT-143, 0603 Parts for Hand Assembly

I'm laying out a rather dense, 4-layer PCB for a hobby project. The parts are a mix of SOT-23 and SOT-143 (basically a 4-pin SOT-23) transistors, with a sprinkling of 0603 resistors and capacitors. Most of the components have a connection to one of the two inner layers (GND and VDD). I'm only going to make one of these, and it will be assembled by hand.

To achieve the desired component density, I'm considering putting vias in the SMT pads. What are the issues with doing this?

None of the parts dissipates any significant heat, so I'm thinking I should use thermals to connect at the inner layers to make it easier to solder.

Is there anything else I should consider?

for hand assembled project i dont see any problems, components arent all that small eighter, as far as you know which end of soldering iron is for holding onto you should do fine. in production line pick and place setup this might cause unpredictable results however and this might might be in violation of several design standards. but for a hobby project all is fair